msem-instigator

Flying
Sire of Empires gets +1/+1 as long as you control another creature, has lifelink as long as you control an enchantment, and has vigilance as long as you control an artifact.

Flying
Cycling {U} ({U}, Discard this card: Draw a card.)

Flying
As long as you control exactly one other creature, that creature gets +1/+1 and has flying.

Defender
Whenever Slumbering Bear is dealt damage, put a +1/+1 counter on it.
Remove a +1/+1 counter from Slumbering Bear: It can attack as though it didn't have defender this turn.

Lifelink
When you attain Sojourner of the Beyond, create two 1/1 white Spirit creature tokens with flying. They gain haste until end of turn.

When Spoiled Prince enters, each player sacrifices a creature with the greatest power among creatures they control.

Lifelink
{2}{W}: Target Elk gains indestructible until end of turn.

Flying
Vanguard — Whenever a creature you control attacks alone, you may put a +1/+1 counter on it.

Flying
When Stratusform Seraph enters, you may return target creature you control to its owner's hand.

When Sun-Blessed Hoplite enters, target creature you control gets +X/+X until end of turn, where X is your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Art of war — At the beginning of your end step, if Teikoku Daimyo dealt damage to an opponent this turn, put a +1/+1 counter on each creature you control that attacked this turn.

Flying

Whenever Twilight Walker perseveres, target creature doesn't untap during its controller's next untap step. (A creature perseveres when it survives damage.)

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Attain {3}{W} ({3}{W}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Identity — Human creatures you control have lifelink as long as you control at least two creatures that share a creature type with Voice of Gaalia.

Armed — Winterborn Savage gets +1/+1 and has vigilance as long as it's equipped.

Prowess
When Adept of Signals enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Tokens you control have “{2}, {T}: Sacrifice this token: Draw a card.”

Flying
At the beginning of your end step, untap another target creature you control.

Flash
If you would upgrade a creature you control, you may put a +1/+1 counter on it instead.
{3}{U}: Put a +1/+1 counter on Affluent Cetanthrope and draw a card.

When Astute Sceneweaver enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flying
At the beginning of your end step, if you cast no spells this turn, scry 2.

Flying
When Aven Merchant enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

When Azutahn Hydromancer enters, you may return target creature with power X or less to its owner's hand, where X is the number of differently named lands you control.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Blind Soulcaller envisions an instant or sorcery card, you may tap target permanent.