Heavenly Breach

Hidden Realm (At the beginning of each endstep, a creature you control can enter or leave this card's
hidden realm.While it is in the hidden realm, it is
treated as though it doesn't exist. It doesn't leave the battlefield)
Whenever a creature leaves this card's hidden
realm, put a promise counter on it.
Whenever a creature with a promise counter
on it attacks, create a 4/4 white angel creature
token with flying tapped and attacking. Exile
that token at the end of combat.