Challenger Troll

Activated abilities of artifacts your opponents control can't be activated. +1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value. −2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Colorless spells you cast cost 2 less to cast. +1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand. −3: Destroy target permanent that's one or more colors.

This creature enters with X +1/+1 counters on it. If damage would be dealt to this creature while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from this creature.

Whenever you gain life, put a +1/+1 counter on this creature.

Put a +1/+1 counter on target creature. That creature gains first strike until end of turn. You gain 2 life. (A creature with first strike deals combat damage before creatures without first strike.)

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

When this creature enters, you gain 5 life.

Lifelink When this creature enters, put a +1/+1 counter on each other creature you control named Charmed Stray.