Atrocitus, Rage of Revenge

You don't lose unspent red mana as steps and phases end.

Magecraft —Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Atrocitus, Rage of Revenge deals 2 damage to each opponent and each creature they control. If it's the third time, add {r}{r}{r}{r}