msem-instigator

Flash
If a spell or ability an opponent controls would cause you to discard a creature card, you may put that card onto the battlefield instead.

You may have Icefang Wurm assign its combat damage as though it weren't blocked.
{4}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

At the beginning of your upkeep, scry 2.
Reveal the top card of your library: If a creature card with flying was revealed this way, Imperial Chimera gains flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Enchant creature
When Inborn Instincts enters the battlefield, enchanted creature deals damage equal to its power to target creature an opponent controls.
Enchanted creature gets +6/+6.

When Intrepid Shieldmate enters the battlefield, target creature gets +1/+1 until end of turn.

Enchant creature
When Join the Pack enters the battlefield, create a 2/2 green Wolf creature token.
Enchanted creature gets +2/+2.

Search your library for a basic Forest card, put it onto the battlefield tapped, then shuffle.
Dominance — If you control the creature with the greatest power or tied for the greatest power, also search your library for a basic non-Forest card, reveal it, put it into your hand, then shuffle.

Enchant creature
When enchanted creature dies, you draw three cards and you gain 3 life.

{4}{G}: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)
When Mountain Bighorn becomes monstrous, you may have it fight target creature you don't control.

Destroy target artifact or enchantment. Its controller gains 4 life.

Destroy target creature with flying. You may put a land card from your hand onto the battlefield.

Rakkiri Archer gets +0/+1 and has reach as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Redleather Armorer gets +1/+1 as long as it's your turn.

When Rotfeeder Slime dies, you gain 2 life for each creature card in your graveyard.

Prevent all damage that would be dealt to creatures and to you this turn.

Sentinel of the Highlands has hexproof as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Whenever Steelcrusher Viking blocks or becomes blocked by a creature, destroy up to one target Aura or Equipment attached to that creature.

Whenever a creature you control becomes monstrous, draw a card.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Trample

Dominance — When Viking Packleader enters the battlefield, create a 2/2 green Wolf creature token if you control the creature with the greatest power or tied for the greatest power.

When Vitality Reclaimer enters the battlefield, you may return target permanent card from your graveyard to your hand.

Vigilance
Whenever Warfield Excavator attacks, you may exile target card from a graveyard.
Warfield Excavator gets +1/+1 for each card type among cards exiled with it.

Whenever Wild Bearmaster attacks, each other attacking creature you control gets +X/+X until end of turn, where X is Wild Bearmaster's power.

Vigilance, reach
When Winter Widow enters the battlefield, you may destroy target creature with flying.