Priest of the Trolls

When Priest of the Trolls enters the battlefield,
untap target Snow permanent.
Whenever Siege Troll deals damage to a player,
you may put an Ursine Influence counter on
target non-token creature. (You gain control of a creature with a number of Ursine Influence Counter
equal or bigger than the converted mana cost of that creature, it is a snow permanent in addition to its
other type)