msem-instigator

At the beginning of your upkeep, rouse 1. Then if you control a creature with power 5 or greater, put a +1/+1 counter on each creature you control. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

As a spell you control is countered by a spell or ability an opponent controls while you control a Mountain, you may reveal Confront the Riddlemaster from your hand. When you do, cast it without paying its mana cost.
This spell can't be countered.
Confront the Riddlemaster deals 4 damage to any target.

When Tantalizing Glutton enters, create a green Aura Curse enchantment token named Just Out of Reach attached to target player. The token has enchant player and “At the beginning of each of enchanted player's opponents' upkeeps, if that player doesn't control a Food, they create a Food token.”

Trample
When Rundfora Communionist enters, return a creature you control to its owner's hand.
Creature spells you cast cost {1} less to cast.

When Lay Bare Ambitions enters, if it was cast, target opponent reveals their hand. Choose a nonland card from it. That player discards that card.
If a spell or ability an opponent controls would cause them to draw one or more cards, instead sacrifice Lay Bare Ambitions and they skip those draws.

Whenever Reclamation Grovesculptor enters or attacks, put a growth counter on target noncreature permanent. It becomes a colorless Forest land and loses all other card types and land types.

Trample

Trample
Whenever Hellfire Titan enters or attacks, exile the top card of your library and up to one target instant or sorcery card with mana value 3 or less from your graveyard. Until the end of your next turn, you may play those cards.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Budding Companion has three or more +1/+1 counters on it, remove them all and transform it.

Trample, haste
When Rejuvenating Elemental enters, remove up to X -1/-1 counters from among creatures you control. Rejuvenating Elemental gets +1/+1 until end of turn for each counter removed this way.

Observation Field enters with three charge counters on it.
{2}, {T}, Remove a charge counter from Observation Field: Draw a card and gain 2 life.
{T}, Sacrifice Observation Field: Shuffle any number of target cards from your graveyard into your library.

When Hollow Hooligan enters, up to two target creatures can't block this turn.
Mirage {1}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Deathtouch, lifelink
At the beginning of combat on your turn, for each creature your opponents control, you may tap an untapped creature you control. If you do, those creatures fight each other.

This spell costs {1} less to cast for each artifact you control.
Choose two —
• Creatures without flying can't block this turn.
• Two target creatures get +2/+0 until end of turn.
• Power Drive deals 3 damage to any target.

Hollow Queen can't be blocked by tokens.
Whenever Hollow Queen deals combat damage to a player or planeswalker, you may remove a counter from a permanent you control. If you do, put a +1/+1 counter on target creature you control.

[+1]: Each opponent loses 1 life for each card you've drawn this turn. Then you draw a card.
[–2]: Shi Hou, the Sun King deals 2 damage to target creature or planeswalker and you gain 2 life. If that permanent was already dealt damage this turn, destroy it.

Forestheart Elemental enters with a +1/+1 counter on it for each land you control.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Hexproof
At the beginning of your upkeep, put a +1/+1 counter on this creature.

Each other nontoken Elf and/or Warrior you control enters with an additional +1/+1 counter on it.
{G}{G}, {T}, Remove two +1/+1 counters from among creatures you control: Create two 1/1 green Elf Warrior creature tokens.

Whenever one or more counters are put on a permanent you control for the first time each turn, create that many 1/1 green Squirrel creature tokens.
{1}{G}{W}, {T}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Northern Express Line enters tapped.
{T}: Add {U}.

Flying
When Sphinx of Ill Omens enters, return target permanent to its owner's hand.
Discard a card: Target creature or player gains hexproof until end of turn.

{1}{R}: Target creature can't block Slippery Salamander this turn.

Flying, trample
Crew 8
When Dragon Emperor's Chariot enters, create a 4/4 red Dragon creature token with flying.
Whenever Dragon Emperor's Chariot attacks, it deals 4 damage divided as you choose among any number of targets.