FOR A NEW HERO
Usually, one week before a new hero there is the offer to buy the New Hero.
You may do so, or you can prepare to have it, increase it step by step and fully upgrade it from day 1 !
To fully upgade the new hero, step by step, without paying money from the start, START COLLECTING EVERYTHING the moment you found about the new hero: Emeralds, Gold, Energy Bottles, EXP potions, Skin Stones Chests, Glyphs, Artifacts and Chaos Cores.
Also, you may find different missions, tasks and/or quests, in the week of obtaining the new hero, and for that missions, tasks and/or quests you may need all types of Consumables: Artifact Keys, Soul Crystals, Chaos Particles, Pet Potions, Pet Summoning Eggs, Sparks of Power, Titan Potions, Titan Skin Stones, Essence of Elements for Titans, Summoning Spheres and Titan Artifact Spheres.
Examples, that you may consider usefull:
go to any hero; then go to Skill Points Available (top, up, center); press "+" button for 10 emeralds and/or for 20; do the same next days; you may find this usefull instead of paying 100 emeralds during the event, after 3 times buying skill points for 10, 20 & 40 emeralds; to consider an amount of 460 skill points for a new hero; maximum level for 1st and 2nd skills are 130 points, the 3rd skill is for 110 points and 4th skill is for 90 points;
go to Merchant; then, go to Town Shop and buy Big EXP Potion; then, go to Soul Shop and buy Huge EXP Potion; finally, 2,948,945 is the amount of EXP the booster uses;
go to Dungeon; then, play it to the end; then, buy Gold from the Merchant, instead of Titan Potions; consider 25.14 Million in Gold to fully level up the new hero;
go to Dungeon, again, & Circle of Summoning; then collect as many Sparks of Power and another Gold to increase the Gift of Elements for the new hero; the amount of Sparks and Gold for this operation is huge - see https://hero-wars.fandom.com/wiki/Guild/Heart_of_Power/Gift_of_the_Elements
go to Merchant; then go to Outland Shop; everyday buy the Large Skin Stone Chest; also collect all skin stones offered for free; once you have the skins, Default Skins need about 30,800 to 31,000, Normal Skins around 50,400 to 50,500, and Champion or Winter Skins require approximately 53,400 to 55,500 Skin Stones; these totals are for upgrading a skin from level 1 to its maximum level (level 60);
participate at ALL Special Events, all missions and all daily & weekly quests AND collect everything that is for free;
OTHERS? - you may complete this by writing in the Guild Chat or Private Chat.
Also, do not forget the Ascension Spire, where you may need other different types of Consumables: Star Manas, Wisdom Crystals, Artifacts, all other Crystals and, maybe, Eternal Seeds.
Also, very helpfull to have some of the Gifts of Dominion !
Payments, that you unfortunately may have to do: all new heroes come with their own Golden Pass/Ticket, only through which you will have access to their first pair of skins.
Payments, you may consider by yourself:
Valkyrie's Favor starting the moment of hearing of the new hero (up to the end of the New Hero event);
Emeralds x4 or x5 only (whenever the case, before and during the New Hero event).
Links, you may consider watching for Cascade event:
Olympus: Triple Hero Wars Events – Save Resources Smartly: https://www.youtube.com/watch?v=Hx-sCVWmZzY
Hero Wars Central: 3 Reasons You Should Level Cascade in Hero Wars Dominion Era: https://www.youtube.com/watch?v=7ruHBZ7cNCM
Hero Wars Info: What Are the Best Buys in the Daily Shops?: https://www.youtube.com/watch?v=e_PmXQnlzIc
Olympus: Cascade Event Leaks: Full Breakdown Before Sept 22! https://www.youtube.com/watch?v=2vWBzb35_-M