Split Seconds

(You may cast a legendary instant only if you control a legendary creature or planeswalker.)

Split Second (As long as this spell is on the stack, players
can't cast spells or activate abilities that aren't mana abilities.)
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)
Add {c}{c}{c} to your mana pool, you don't lose this
mana as steps and phases end