Remorseful Riftwalker

Veil {1}{r} (You may cast this card for its Veil cost. If
you do, exile it instead of putting it on the battlefield.
You may pay its regular mana cost any time you
could cast a sorcery and bring it to the battlefield.)
When this card is cast into exile, gain control of
target creature for as long as Remorseful
Riftwalker is in exile.
Their stain cannot be cleansed.