I wanted to suggest a set designed for hardcore gamers.
The set will have up to 200 heat levels (do not flame please read on). The set will start with 0 stats at level 1, shield will have -100% on all status effects ie full red bar. When it hits 200 heat level it will be "as strong as the starting gear on heat10". While wearing this gear at level 50/100/150/200 you unlock 4 passives related to crows and mist energy.
PS: You need to have on full gear to get the passives to work.
50: You gain "1 crown" for a killing blow. If you take any damage you will be unable to gain any "crown proc" from this floor. But normal crown can still drop on the floor.
100: Your shield no longer has -100% all status effects instead its 0% neutral on all status effects.
150: Dying with this gear no longer costs Double Mist Energy to revive.
200: You gain "1 mist energy" for a killing blow. If you take any damage you will be unable to gain any "mist energy proc" from this floor.
Now I know this will seem absurd but it will really be hard to play with this gear in any deep levels. Imagine going around with 0star gear into deeper levels. Any damage will really mess your passives you worked hard for. Even traps.
While I'm heavily against getting free energy just for killing an enemy (think of the arena looping! The Mini-Jelly spawner abusing!), and even more heavily against the no-damage idea (there are some cases where you HAVE to take damage), we DO need high end gear. IE, 6* gear that requires a huge amount of materials/more than one item (IE Voltedge + Glacius = Flash Freeze or summat).