Bloodlust

You call apron the god of blood, Shezmu. Upon impact, this spell will do 4d4 of damage. If you kill an enemy with this spell, the next spell you use(that isn’t bloodlust) will do 1d4 more damage. This attack stacks, instead of losing bloodlust next turn, it keeps adding d4s until you cast a different spell (ex: you cast bloodlust and kill a goblin, next turn, you use bloodlust on another goblin and kill that one as well, then you use fire bolt and do an additional 2d4 of damage).

at the end of a battle, you lose all d4s you have accumulated over the corse of the fight.