Ei, Archon of Eternity

Indestructible, Double Strike
{u}{u}{r}{r}: Creatures you control gain Double
Strike until end of turn.
{u}{u}{u}{r}{r}{r}: Ei, Archon of Eternity deals 6
damage to each of your opponent's creatures
during each of their main phase, combat phase,
and end step.
Damage dealt by Ei, Archon of Eternity doesn't disappear as steps and phases end.
"So ephemeral. This is why reaching
Eternity is desirable."