Thunder Child
This Paladin Subclass is based on Raiden from Mortal Kombat with Optional Features to play as a Thor-esk character. It focuses on being a protector of the human realm and being blessed by the god of thunder. For flavor's sake you can ask if Raiden can be a minor deity or change the name of another god. This also works well to just choose one of the elder gods.
Oath Tenants.
Protector of the Realm: You are one of god's chosen for the protection of the realm. Gods can not always be bothered to have a hand in the whims of people so you take up the burden happily.
Human Guardian: You are on the realm to take away power from those who threaten the people of the gods.
Blessed & Thundered: You are obligated to use your thunder when possible to increase the strength of your god.
Positive Conducting. Like metal conducts electricity, so do the people around you. Let your unwavering energy surge into all those around you, so they may be transformed into something greater.
Oath Spells. These are additional learned spells that you take at the corresponding levels. You may take any of the optional spells and forfeit a different spell from the same level or higher.
2nd - Call Lightning, Detect Magic
5th - Lightning Bolt, Thunder-wave, (optional) Thunderous Rebuke
9th - Crusader's Mantle, Daylight
13th - Thunder Step, Arcane Gate, (optional) Haste, (optional) Storm Sphere
17th - Maelstrom, Lightning Rod (homebrew), (optional) Power Word Stun, (optional) Chain Lighting
Storm Smite. When you gain this class at 2ndd level, the radiant damage of your divine smite is replaced by thunder or lighting damage (your choice).
Lightning Rush. At the 2nd level, you can fly forward a make a melee strike. You can fly your movement speed, add your athletics to your attack. If you fail to make the strike you fall prone. This feature replaces divine health.
Aura of The Storm (optional). At the 6th level, you may replace a divine aura with this feature, you gain a flight speed of your movement speed and make lightning appear around you while flying. This also increases spell attack rolls by 1 while in the aura of 10 ft. This replaces your other aura as a paladin.
Reliant Lighting. At the 7th level, You can use any of your oath learned spells once per day without consuming a spell slot.
Thunderous Blessing. (Optional feature would replace reliant lightning) Starting at 7th level, you may imbue a single, nonmagical melee weapon of your choice with the fury and might of your God. This process requires 8 hours of uninterrupted prayer to your deity, detailing your accomplishments, why you must be granted such power, and how you are worthy of such a weapon. Upon success, lightning strikes the weapon, and becomes attuned to you, but doesn't expend an attunement slot. This weapon becomes a +1 weapon, and you may cast Lightning Lure through this weapon when you use an action to attack with it. Additionally, this weapon gains the Thrown (range 30/120) property if it doesn't already possess it. As a bonus action, you may call your imbued weapon to you, which travels at a speed of 90 ft in a straight line and can find its way back to your hand. If this weapon is on another plane, it appears on your next turn as if using the Plane Shift spell in the same space as you, and returns to your hand. Anyone else attempting to wield or otherwise manipulate this weapon must succeed in a Strength check with a DC equal to your 10 + your Paladin level, unless it is aligned with your diety. On failure, the weapon is effectively too heavy to move. If your imbued weapon is destroyed, you may repeat the imbuement process. At level 15, you may imbue a Hammer of Thunderbolts or a Dwarven Thrower with these properties, ignoring the nonmagical rule. In addition, you do not need a Belt of Giant Strength or Gauntlets of Ogre Power to become attuned to a Hammer of Thunderbolts or Dwarven Thrower.
Blood Lightning. At the 16th level, You gain 3 6th level spell slots and when casting a spell at 3rd level or higher it appears red. while doing so you can add an additional 1d10 lighting damage.
Fatal Lightning. At the 20th level, you can call down red thunder that will find a target you choose. Make a spell attack. If it hits and they are under 111 hit points they are instantly killed in a flash of red lightning. If they are over 111 hit points it will deal 5d12 lightning damage. This can only be used once per long rest.
Envoy of the Storm. (Optional replacement for Fatal Lightning) At 20th level, you can use an action to channel the essence of the storm into you to become an avatar of the storm. For 1 minute, you gain the following benefits:
When you hit a creature with an attack on your turn, the creature takes an additional 3D8 lighting, thunder, and cold damage.
Creatures cannot benefit from the Lightning Absorption trait from damage you deal.
A tornado of thunder and wind forms around you in a 30-foot radius. The first time any enemy creature enters the storm or starts its turn there during a battle, the creature must succeed on a Wisdom saving throw or become frightened of you for 1 minute or until it takes any damage. Attack rolls against the frightened creature have advantage.
Once you use this feature, you can't use it again until you finish a long rest.