msem-instigator

Constructs you control have haste.
When Urak, Voice of the Horde or another Construct you control enters, creatures you control get +1/+0 until end of turn.
Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)

Lifelink
Creature tokens you control get +1/+0.
Whenever a token you control enters, each opponent loses 1 life and you gain 1 life. This ability triggers only once each turn.

Whenever a creature you control dies, put a +1/+1 counter on AOSE Xenocultivator. If this is the third time this ability resolved this turn, AOSE Xenocultivator deals 3 damage to any target.

Whenever you cast a Dwarf or Elf spell, exile the top card of your library. You may play it this turn.
Whenever you cast your third spell each turn, Celitiene deals 2 damage to any target. If you control a Dwarf, Celitiene gets +2/+2 and gains trample until end of turn. If you control another Elf, you gain 2 life.

Artifacts you control have “{T}: Add one mana of any color.”
{2}{R}{G}: Create a 3/2 green Crocodile creature token with trample. It gains haste until end of turn.

{1}{R}{G}: Feral Exemplar gets +2/+2 until end of turn. Activate only once each turn.
Ferocious — Whenever a creature you control with power 4 or greater attacks, that creature gets +X/+X until end of turn, where X is its power.

First strike, haste
Other creatures you control with flash or haste have first strike.

When Forserval enters, creatures you control get +1/+1 and gain haste until end of turn.

Trample, haste
Herald of Untold Riches gets +1/+1 for each color among other spells you've cast this turn.

Trample
Harmony — Put a +1/+1 counter on target Warrior you control. You gain 1 life.
Whenever one or more Warriors you control deal combat damage to a player, harmonize. (Trigger up to one harmony of a permanent you control.)

{T}, Sacrifice a land: Destroy target land.

When Kessig Wolftamer enters, create a 2/2 green Wolf creature token.
{4}{R}{G}: Transform Kessig Wolftamer. Activate only if it's attacking.

Whenever a creature with power 4 or greater you control enters, it gains haste until end of turn.
{T}: Add {R} or {G}.
{4}{R}{G}: Create a 4/4 red Dragon creature token with flying.

Sera of Coppercove attacks each combat if able.
Whenever Sera of Coppercove attacks, it fights target creature you don't control.
{1}{R}{G}: Sera of Coppercove gets +3/+3 until end of turn.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever Sullivan's Heralds or another creature you control becomes renowned, add mana equal to the number of +1/+1 counters on it in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

This spell can't be countered.
{R/G}: Target spell can't be countered.

Discard a card: Tender Warden gets +2/+2 until end of turn. Activate only during your turn.

Whenever a creature you control enters, Timid Thunderhorn gets +X/+X until end of turn, where X is that creature's power.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{4}{R}{G}: Twinblade Paragon gains double strike until end of turn.

At the beginning of combat on your turn, if you control a creature with power 4 or greater, put a +1/+1 counter on Wilderkin Zealot.
{R}{G}: Target creature gains trample until end of turn.

{2}{R/G}: Wildershrine Warden gets +2/+2 until end of turn. You may have it assign its combat damage this turn as though it weren't blocked. Activate only once each turn.

Voracious 1 (As this enters, you may sacrifice an artifact or creature. If you do, it enters with a +1/+1 counter on it.)
At the beginning of combat on your turn, if you sacrificed a permanent this turn, target creature you control gains trample and haste until end of turn.

Aurashaper and Aura spells you cast cost {1} less to cast.

Amleth, Royal Claimant can't be blocked by creatures with power 3 or less.
At the beginning of your end step, if you control three or more tapped creatures, create a 4/4 white Angel creature token with flying and vigilance. Otherwise, create a 1/1 white Soldier creature token.

Anomalion enters with a +1/+1 counter on it.
{1}{G}{W}: Permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)