msem-instigator

Destroy target creature. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Target creature gets +1/+1 until end of turn for each creature token you control.
Put the bottom card of your library into your hand.

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Observing Guardian enters, if tribute wasn't paid, create a 2/2 white Cat creature token.

Deathtouch
Whenever another creature dies, its controller discards a card at random.

Flash
Whenever Iken Company Nightwalker deals combat damage to a player, put a +1/+1 counter on it.

{W}, {T}: Tap target creature.

Whenever Unstable Vein enters or leaves the battlefield, choose one —
• Put a +1/+1 counter on each of up to two target creatures.
• Unstable Vein deals 2 damage to target creature with flying.

Augmented — When Dead End Adventurer enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, destroy target creature you don't control.

At the beginning of each end step, if you gained life this turn, you get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

{T}: Add one mana of any color.
{2}, {T}: Draw a card. Activate only if you sacrificed a permanent or discarded a card this turn.

Until end of turn, target creature gets +X/+X and can only be blocked by X or more creatures.

Flying
Whenever Rubble Scavenger deals combat damage to a player, you may return target artifact card with mana value 4 or less from your graveyard to the battlefield.

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

({T}: Add {G} or {U}.)
Soaring Rainforest enters tapped.
{1}, {T}: Add {G}{G} or {U}{U}.

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)
{1}{W}: Target creature with a +1/+1 counter on it gains lifelink until end of turn.

Enchant creature
Enchanted creature can block any number of creatures each combat.

Hurtling Swine attacks each combat if able.

At the beginning of your upkeep, if Nightmare Riders is in your graveyard, you may mill two cards.

Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Face-down creatures you control get +1/+1 and have flying.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Unstable Borer attacks each combat if able.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Curious Cubs has first strike as long as its attacking.
When Curious Cubs has three or more +1/+1 counters on it, remove them all and transform it.

Journey three times. (Exile the top three cards of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

Apostle of the Elders has lifelink as long as it has a +1/+1 counter on it.