Triss Merigold, the Fearless

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, Triss Merigold deals 2 damage
to each opponent and each creature they control.
If it's the third time, add {r}{r}{r}{r}.