Kirya, Justice-Bringer

{r}{w}{u},{t}: Put a justice counter on up to one
target creature, at the beginning of your upkeep,
destroy that creature if its owner attacked you
with a creature during their last turn.
Whenever a creature with a justice counter on it
dies, you may exile the top card of your library.
Until end of turn, you may cast nonland cards
exiled with Kirya this turn without paying their
mana costs.