Werewolf
If you're a warrior, then you'll want to commit yourself to the Werewolf subrace: it offers STR and DEX drives and a weapon-based skill which causes the monster to bleed, among other things. However, the most noteworthy ability it has is a little-known skill called Snarl, a quick-cast skill which inflicts Fear upon the monster. It can be used twice in a single turn. When used alongside Terror Eater, the results can be utterly devastating.
Its level 10 skill is also very impressive: at the cost of 294 SP every turn, your melee/ranged damage output is multiplied by 1.75. Magic weapon damage is multiplied by 2.
Aside from the standard version (earth, light secondary), which is automatically given to guardians as a no-drop, you can also buy separate elemental versions of the subrace:
Keep in mind that the Advanced Werewolf armor in the shop is completely identical to the no-drop version - there's no need to buy it unless you're an adventurer.
Vampire
This is the ideal subrace for beastmaster mages, as it offers CHA and INT drives along with a meta-defining skill called Mesmerize, which uses CHA for infliction and can Control the monster for several turns at a time. Like Snarl it's only usable twice per turn, however.
Vampire, like Werewolf, also has a level 10 transformation skill. However, instead of costing 294 SP per turn, it costs 131 MP and 196 SP. While it grants the same initial boost as Werewolf, you take a damage penalty of x7/8 to heal your HP for 1/7 of the damage dealt.
The no-drop version is darkness, with a wind secondary. Alongside it, Vampires can also use:
Werepyre
If you run a hybrid build, then Werepyre is absolutely the optimal subrace for you. However, if you do not, then you won't get much use out of it. This is because Werepyre has a skill called Force of the Night, which causes you to use STR and INT for your stat bonuses to damage and BTH, rather than STR and DEX or INT and DEX. Note that while Force of the Night is optional and toggle-able in Werepyre's base form, in its beast form you are locked into using it.
Speaking of its beast form, Werepyre has the strongest transformation of all the subraces. Rather than only paying 75% the cost of a standard melee skill, you instead pay the full price of 261 MP and 196 SP. In turn, your melee damage is multiplied by 2, with no penalties at all. The subrace also has STR and INT drives compressed into a single toggle, as well as a toggle which causes you to regenerate 40 SP and 53 MP every turn at the cost of a measly, negligible 15 HP. Last but not least, Werepyre has a skill called Terror which inflicts Panic on the monster, reducing their damage by 36%. It can only be used once per turn, but it does stack with itself, and remains for the rest of the battle unless a save is made.
The advanced/no-drop version compresses earth and darkness, resisting both at 40%. Werepyres can also buy the following elemental variants:
Location: Darkovia
Blazing Bloodzerker
This armor passively boosts weapon damage by 20% for small HP cost and it has an exceptional SP cost skill that boosts all normal player attacks and even some skills that are compressed into weapons and shields. This armor is effectively a superior and ele-locked subrace skill. Since it ele-locks and boosts all normal player attacks it can turn Eat Fear and Blade of the Thornful Rose into fire damage. This can be used with all the greatest boosting items and Terror Eater to deal 20K-40K+ damage in only 2 turns and even more with Freeze status items, elevuln etc. https://imgur.com/272CBbI Caption: Only two successful Snarls and no statuses except Fear used.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
Tinkerer (PREMIUM)
This phenomenal armor is available through the 6000 Z-Token package. Its standard attack is 2 hits, both equally powerful. It defends against both fire and energy, but not only that, it has two strong 4-hit skills for both elements.
Location: 6000 Z-Token package
Headless Horseman
This armor is a great option for warriors in particular, due to the fact that it has a strong weapon-based skill that uses very little SP.
Location: Valencia -> Golden Giftboxes -> Rare Shop
Pyromancer Bloodmage (RARE)
Without a doubt, this is the best FO fire armor in the game for mages and hybrids. It boosts all spell damage by 50%, and comes with a fire spell that receives enormous EleComp. It used to be a reward for defeating Caecus in the Void, but sadly it's rare now.
Location: None
Moglord Tortress (RARE)
This armour resists against both fire and water, and has a powerful 3-hit Water skill. If you have it and you need compression, definitely consider using it.
Location: None
Supreme Overlord's Dynasty
A standard FO armor with a slight lean towards power, and thus slightly lower accuracy. The standard attack consists of 4 equally powerful hits, and every turn, there's a small chance that you'll be given Celerity, allowing you and your pet/guest to attack twice in that turn. While the above options are all superior, this is the best non-rare offensive fire armor that doesn't require you to spend real money.
Location: Travel Map -> South -> Alnaphar -> Overlord Set
Kindred Spirits' Valiance
THIS ARMOR IS A MUST-HAVE. IT IS, QUITE LITERALLY, THE BEST OFFENSIVE ARMOR IN THE ENTIRE GAME. It's fairly simple why. The Focus skill allows you to stack up Tranquility Charges. With the full set equipped, you can gain around 50-60 charges every time Focus is used. The charges stay with you in-between battles, and there's seemingly no limit to how many you can stack, if you're patient enough. Kindred Strike uses up 200 Tranquility Charges every time it's used, and it boosts melee/ranged weapon damage by 600% and magic weapon damage by 766%. You can also use charges on the weapon to make it auto-hit for the remainder of the turn, and on the shield to give yourself a sizable HP or SP heal.
The general strategy is to battle the Combat Practice Trainer and pre-stack as many charges as possible. Then, you can use those charges for as many nukes as you'd like.
Location: Kindred Set
Hydromancer Bloodmage
A water clone of Pyromancer Bloodmage. Somewhat worthwhile for mages and hybrids, but it still can't top Kindred. Its armor skill is the strongest water spell in the entire game.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
W.H.E.E.L.
Though it's ugly as sin (in my humble opinion), W.H.E.E.L. is a solid armor for people who are bored of trivializing the game with Kindred. It resists water and earth at 40% each, and has a powerful 3-hit water skill.
Location: Crossroads -> Farmlands -> Burp War 2014
Human Fisher
Essentially a water version of Headless Horseman.
Location: Valencia -> Golden Giftboxes -> Rare Shop
Moglord Tortress (RARE)
Already mentioned in the fire section.
Location: None
Griffinrider Mount (PREMIUM)
The best wind armor in the entire game, matched only by Lord of the Skies. In its Mounted state, it's a standard FO armor, with an 80% chance of doing 1 hit, 80% damage, and a 20% chance of doing 3 hits, 180% damage. However, in its Unmounted state, it's locked into dealing wind damage, and as a result, gets a massive damage boost of x1.84. Pairs well with Robocockatrice or Fu-Dog due to their ability to Petrify the monster.
Location: 20000 Z-Token package
Lord of the Skies
Location: 20000 Z-Token package
Tyrannochicken Rex Rider (SEASONAL)
If you don't have either of the above armors, then this is the next best option. Basic attack is 3 hits, all equally powerful, and it also has a strong 2-hit skill. It returns every year during Grenwog, but is rare otherwise.
Location: Grenwog
Offensive Test Armor
This is worth picking up if you're waiting for Grenwog to come around. It's a reasonably strong FO wind armor, that actually costs nothing at all.
Location: Ballyhoo -> Advert -> Rare Item Shop
Cryomancer Bloodmage
Ice variant of the other Bloodmage armors listed already.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
Hand of Tera'Suul (PREMIUM)
Ice armor that has good resistance to Fire. Has two skills, one being a weapon based skill and the other being an FSB skill that inflicts a 9999-turn Burn that can stack with itself (FSB skill requires armor, shield, and weapon equipped).
Location: 50000 Z-Token Package
Graverider Mount (PREMIUM)
An ice clone of Griffinrider Mount. Pairs well with Super-Heated Boiler Buddy (rare) due to its ability to inflict Thermal Shock on the monster. Though great, it's outclassed by Cryomancer Bloodmage for mages and White Howler for warriors.
Location: 20000 Z-Token package
Horo-Show Void Vigilante
This is the best non-premium ice armor available. It has a strong 2-hit basic attack and an immensely powerful 2-hit skill.
Location: Twilly -> Anniversary Events -> The Dragon of Time -> BONUS
Ice Cream Crusader
A strong FO ice armor with 2 basic attacks: one being 2 hits, the other being 3 hits. Every hit has a small chance of doing 25% greater damage.
Location: Warlic's Shop -> Mastercraft Sets -> Dessert Set
Fatal Chimeran Vindicator
Though it's only MO rather than FO, this armor is exceptional. Standard attack is 2 hits, and it also has two skills: one poisons the monster, and the other performs a powerful fire-element blast. However, due to the fact that it has two MC bonuses, the armor costs almost 100 million gold so be aware of that before doing the quest.
Location: Warlic's Shop -> Mastercraft Sets -> Chimeran Set
Bloodstained Morningstar Bloodline
While it's FO, Chimeran Vindicator still manages to be better. That said, this armor is worth mentioning; it has a secondary resistance to darkness (41% at level 150), and every hit deals 6% more damage if the prior hit (within the round) connected.
Location: Morningstar Set
Samurai Warlord O-Yoroi
This is another very nice option. Like the Chimeran Vindicator it is MO, and while it only has one skill as opposed to two, it's a powerful 2-hit weapon-based skill that actually uses the element of your weapon.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
W.H.E.E.L.
Already mentioned in the water section.
Location: Crossroads -> Farmlands -> Burp War 2014
High Oracle's Taladosian Robes
This is a particularly great option for mages. The basic attack has a 50% chance of doing 1 hit, 70% damage, a 40% chance of doing 2 hits, 120% damage, and a 10% chance of doing 3 hits, 170% damage. In addition, the 3-hit skill is not only the strongest energy skill in the game, but one of the strongest skills period.
Location: Talados Set
Tinkerer (PREMIUM)
Already mentioned in the fire section.
Location: 6000 Z-Token package
StarSlayer (SEASONAL)
StarSlayer is a fine armor that returns every year on May 4th, and is available through the Void Challenge. The armor has two basic attacks: a 50% chance of doing 1 hit (+5 BTH) followed by 2 hits (+0 BTH), and a 50% chance of doing 4 hits (+5 BTH). The skill chokes the monster, making them do about 60-70% of their normal damage, but it also has a damage penalty to compensate.
Location: The Void
Megingjord
This armor has a 3-hit basic attack when wielding a melee/magic weapon, and a 2-hit basic attack when wielding a ranged weapon. While the armor is only Neutral rather than FO, you can click the waist to deal 25% more damage (melee/ranged) or 33.3% more damage (magic) at the cost of 98 SP per turn, while not taking any more damage.
Location: Thunder Mountain
Loco Costume (SEASONAL)
Though not amazing for pure damage since it's only Neutral, this armor is as useful as it is fun to use. It has 3 attacks, each with an equal chance of occurring. The first attack consists of 3 equally powerful hits; it only deals 54.8% damage, but it has a high chance of paralyzing the monster, as well as a +5 BTH lean (already factored into the stated damage percentage). The second attack consists of 2 hits and deals 106.25% damage, but has a -5 BTH lean (already factored in). The third attack consists of 4 hits, has no BTH lean, and deals 50% damage, but it heals you equal to the amount of damage dealt.
Location: April Fools -> 2012
White Knight Z (Z-TOKEN)
Without a doubt one of the best light armors in the game, if not the best. Standard attack is 2 hits, nothing special, but its skill is incredibly powerful due to the massive EleComp it receives, making it not only the strongest light skill in the game, but the strongest skill period (discounting Kindred Strike).
Location: Guardian Tower -> Guardian Shop
Lumenomancer Bloodmage
Light variant of the other Bloodmage armors listed already.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
Light Realm Champion (PREMIUM)
Light armor. Has two skills, one being a weapon based skill and the other being a FSB skill that inflicts a 9999-turn Blind that can stack with itself (FSB skill requires armor, shield and weapon equipped).
Location: 50000 Z-Token Package
Ultimon's Armor
Not only is this one of the best non-rare, F2P light armors around, but it is the best armor in the game for combating Shadow monsters. It compresses light and darkness, and it has a skill that seeks between the two elements. However, it costs almost 100 million gold and Ultimon is considered to be one of the most difficult boss fights in the game, so do keep this in mind.
Location: Ultimon's Fortress -> Finale
Fiend of Light
A fully offensive light armor. Has a skill that can inflict Soul Rend, stunning them for one turn and increasing the enemy's vulnerability to dark damage up to a max of 200%. The skill is locked to fire, and pays a -45.8% additive damage penalty for the Soul Rend effect. Weapon effects and specials may occur, and receive a boost from the armor and are locked to fire.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
ShadowWalker of Time (PREMIUM)
One of the best armors in the game for warriors. The standard attack consists of 2 hits, and the armor has two skills. The first does 50% more damage than normal, but has a high chance of giving the monster Celerity afterwards. The second skill inflicts the Fragile status, giving the monster -33 END for 9999 turns, and this effect stacks with repeated use. When used with the shield and weapon (which has a chance of giving you Celerity), the Celerity chance is doubled.
Location: Buy Heromart Calendar 2017 "Year of Adventure" -> Redeem code in Master Account
Terror Raiment (Z-TOKEN)
Has two standard attacks: a 50% chance of doing 1 hit, 80% damage, and a 50% chance of doing 4 hits, 120% damage. At the start of the battle, it inflicts Fearful Presence which can make your opponent unable to act for the first turn. The skill inflicts Fear for 5 turns, and each turn the monster has a 25% chance of not acting. Repeated use of the skill can increase this chance to 100%.
IMPORTANT NOTE: If you pick up Terror Raiment, you'll also need to pick up the weapon, shield and misc alongside it. The armor on its own is mediocre but the full set's synergy is immaculate. The Full Set Bonus increases the skill's Fear infliction chance by 11%. You can click the weapon's handle to Eat Fear, an attack which removes your opponent's Fear status to deal monstrously high damage, and you can click the shield to remove your opponent's Fear to heal yourself for an impressive amount.
Location: Terror Set
Doom Knight
Old Lean Fully Offensive armor with a Fire and Darkness seeking. When it deals fire damage it deals 1.67x damage in the form of elecomp but when darkness it is 1.5x.
Info: http://forums2.battleon.com/f/fb.asp?m=21811461
Art: http://forums2.battleon.com/f/fb.asp?m=21799033
Ebony Sepulchure Armor
Armor with a 1.76x elecomp old lean skill that looks like a black armored DragonFable Sepulchure. Against not undead monsters the skill does half damage and attempts to turn them undead. If a monster is undead or turned undead then the skill does 110% damage instead of half damage making its damage an effective 1.94 elecomp which is almost as good as all the best skill armors in the game. The turn undead effect has a relatively high chance of 63% against almost all monsters.
Info: http://forums2.battleon.com/f/fb.asp?m=21811461
Art: http://forums2.battleon.com/f/fb.asp?m=21799033
Angel of Souls
The best option available if you don't want to spend real money. The standard attack is 2 equally powerful hits. The skill is weapon-based, but instead of using SP, it uses a negligible amount of HP (though the cost is increased for magic weapons). Considering how little the skill costs to use, and how high the damage can be with the right weapon and damage boosters, this armor is easily the best F2P darkness armor in the game.
Location: Death's Domain -> Retrieve 100 hourglasses
Evolved Void of Nulgath
Has a Wind secondary. 80% of the time, you'll do a 2-hit attack for 90% damage and 20% of the time, you'll do a 3-hit attack for 140% damage. Its MC is similar to Zealot's Wrath (Ranged), Tempest Scimitar, and Atrea Dream Dagger in that you get a 15% chance to hit a Lucky Strike instead of 10%. Works well with Zealot's Wrath.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop
Ultimon's Armor
Already mentioned in the light section.
Location: Ultimon's Fortress -> Finale
Shinyaro Form (RARE)
4 element compression. 45 base resist to water, earth, light and darkness. Has a weapon-based skill that follows your weapon's element, with the full SP cost of 392 due to a lack of Elecomp; reduces the monster's END by 50 for one turn, but has a damage penalty of 25% to compensate. The END save uses STR/DEX/INT based on your weapon type.
Location: None
Griffinrider Mount (PREMIUM)
Already mentioned in the wind section.
Location: 20000 Z-Token package
Graverider Mount (PREMIUM)
Already mentioned in the ice section.
Location: 20000 Z-Token package
Algern's Carapace
Algern's Carapace is a Neutral armor, with a maximum level of only 131. However, as it's locked into dealing darkness damage, it receives impressive EleComp allowing it to outdamage FO level 150 armors. In addition, it gets a skill which costs 94 SP and drains your opponent's HP, healing you equal to the damage done.
Location: Seekrat -> Part 7
Svadilfari's Oath
Like Algern's Carapace, Svadilfari's Oath is a Neutral armor that's locked into a single element and thus receives high EleComp, though it deals energy damage instead of darkness. However, due to being level 150, it's more accurate than Algern's. In addition, while it has no armor skill, it has a special attack that can paralyze the monster for up to 3 turns.
Location: Thunder Mountain
Frozen Dragonslayer
At first glance FDS seems like nothing special. A simple, neutral armour with a 1-hit attack. However, the usefulness lies in the skill, which triggers on dragons to deal Void damage.
Location: Valencia -> Golden Giftboxes -> UltraRare Shop