msem-instigator

Sun-Dappled Paragon enters with a +1/+1 counter on it for each other creature you control.
Whenever another creature you control enters, put a +1/+1 counter on Sun-Dappled Paragon.

Whenever a land enters, Collapsing Realities deals 2 damage to each player.

Abound. Then search your library for a creature, instant, or sorcery card, reveal it, put it into your hand, then shuffle. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

{T}: Another target Warrior you control gets +1/+0 and gains haste until end of turn.

Target creature you control deals damage equal to its power to target creature you don't control. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

When Guardian of the Wurm enters, create a 6/6 green Wurm creature token with trample.

Deathtouch

Choose one or both —
• Each player sacrifices an artifact.
• Each player sacrifices an enchantment.

Civilization's Cost deals damage to each player equal to the number of nonbasic lands that player controls.
Flashback {R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

First strike (This creature deals combat damage before creatures without first strike.)
When Zephyr Rider enters, you may have another target creature you control gain first strike until end of turn.

Target noncreature artifact you control becomes a 0/0 artifact creature. Put three +1/+1 counters on it.

Target creature gets +2/+2 until end of turn.
Wanderlust — If you control four or more differently named lands, that creature gets +4/+4 until end of turn instead.

The Mythical Zhiwu enters with four +1/+1 counters on it.
{1}, Remove a +1/+1 counter from a creature you control: Target creature gets -1/-1 until end of turn. Activate only as a sorcery.
{1}, Remove a +1/+1 counter from a creature you control: Each opponent loses 1 life and you gain 1 life.

Put target creature into its owner's library third from the top.

When Sarrutu Worldbinder enters, create two 1/1 red Elemental creature tokens.
{1}{U}, {T}: Elementals you control gain flying until end of turn.
{2}{R}, {T}: Elementals you control get +2/+0 until end of turn.

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

Whenever you play a land, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{1}{G}{U}{R}, Sacrifice three Clues: Exile cards from the top of your library until you exile three nonland cards. You may cast any number of those cards without paying their mana costs.

You may exert Awoken Elemental as it attacks. When you do, Awoken Elemental fights another target creature. (An exerted creature won't untap during your next untap step.)

Whenever a nontoken creature you control dies, create a 1/1 black Spirit creature token with flying.
[+1]: Each opponent loses 2 life and you gain 2 life.
[–2]: You may sacrifice a creature. When you do, destroy target nonland permanent.

You may play an additional land on each of your turns.
{1}{B}{G}, Sacrifice a land: Draw a card.

{T}: Add {C}.
Motley — {T}: Add one mana of any color. Activate only if there are five or more names among nonland permanents you control.

{U}: If Engrossed Reader doesn't have flying, put a flying counter on it.
{1}{U}: If Engrossed Reader has flying, draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on Engrossed Reader.
{1}{U}{U}: If Engrossed Reader has a +1/+1 counter on it, it becomes a copy of another target creature until end of turn.

Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Defected Explorer.

{2}{B}: Reclaimed Kalak gains indestructible until end of turn.
Revive {3}{W} ({3}{W}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever Ming Fleet Privateer attacks, put a menace counter on target creature in its pack. (Two or more creatures you control with equal power are in a pack.)