Margit the Fell Omen

At the beginning of your upkeep, you may reveal a creature with mana value 3 or less from your hand,
if you do, exile it facedown underneath this card.
When Margit the Fell Omen dies, you may exile
target creature with mana value less than or equal to
the combined mana of the cards exiled with this
card.

Margit the Fell Omen's power is equal to the
number of cards exiled with its effect.