Ellen, Fate Bewitched

Defender (this card can't attack)
Whenever you take control of a creature,
you gain an defiled soul counter.
{x}{t}, Pay 3 life: Take control of target creature
with Mana cost X or less until end of turn.
If you have 5 or more defiled soul counters,
you may instead swap control of
this card with target player.
If you do, you may draw a card.