Reija Kou, Ephemeral

Flash, Haste, Double Strike, Ward {5}
When Reija enters play you may counter a spell.
Night—{b}: Other non-black creatures are -2/-2 (cannot reduce toughness less than 1) until end
of turn. Use no more than once per turn.
Critical—{t}: Destroy target creature. If its power
is greater than Reija's power you lose Life equal
to the difference.