msem-instigator

When Gate of Realms enters, you may search your library for a land card, reveal it, and put that card into your hand. If you do, shuffle.
{10}, {T}: Gate of Realms deals 3 damage to any target. This ability costs {1} less to activate for each different name among lands you control.

Meteor Volley deals 3 damage to each creature.
Reprise {4}{R}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

Target creature gains haste and trample until end of turn.
Fabled {3}{R/G}{R/G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

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.)
If you would gain life, you may put a +1/+1 counter on this creature instead.
When this creature has toughness 20 or greater, you win the game.

Other legendary creatures you control get +1/+1.
At the beginning of your upkeep, you may search your library for a legendary card, reveal that card, and put it into your hand. If you do, you skip your draw step this turn and shuffle.

Choose one —
• Return target permanent card from your graveyard to your hand.
• Destroy target artifact or enchantment.

You may have Crossroads Town enter tapped. If you do, search your library for a basic land card, reveal it, then shuffle and put that card on top.
{T}: Add {C}.

This spell costs {2} less to cast if you sacrificed a Clue this turn.
Target player discards two cards.

{T}, Pay 1 life: Add {B} or {R}.
{1}, {T}, Sacrifice Grim Slums: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Destroy target artifact and all other artifacts with the same name as that artifact.
Draw a card.

Enchant creature or planeswalker
Enchanted permanent can't attack or block and loses all abilities.

Flash
Flying
When Justiciar Overseer enters, the next 2 damage that a source of your choice would deal to you and/or permanents you control this turn is dealt to any target instead.

Bloodline Zealot gets +2/+0 and has menace as long as you've sacrificed a permanent this turn.

Flying
If Mindbreaker Sphinx would deal combat damage to a player, you may prevent it. If you do, that player mills X cards, where X is Mindbreaker Sphinx's power. If two cards that share a card type were milled this way, put a +1/+1 counter on Mindbreaker Sphinx.

Scoured Mesa enters tapped.
{T}: Add {W}.
Desertcycling {1}{W} ({1}{W}, Discard this card: Search your library for a Desert card, reveal it, and put it into your hand, then shuffle.)

Scry 2, then reveal the top or bottom card of your library. Creatures you control get +X/+X until end of turn, where X is that card's mana value.
Draw a card.

Mistwake Hydra enters with X +1/+1 counters on it.
Creatures with power less than Mistwake Hydra's power can't block it.

Reach
Art of war — At the beginning of your end step, if Hinode Ranger dealt damage to an opponent this turn, put a +1/+1 counter on it.

Whenever another enchantment you control enters, put a +1/+1 counter on Neo-Soul Prophet and conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Put a +1/+1 counter on each creature you control. Repeat this process if you control a Soldier. Repeat this process again if you control a Knight.

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

Return X target creature cards with mana value 3 or less from your graveyard to the battlefield, then choose one of them and exile the rest.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform it.)
When Mystery of the Dying Herds enters, create a 0/2 white Ox creature token.
A creature you control dies.
You have 4 or more life than your starting life total.

At the beginning of your end step, if you cast no spells this turn, you may return Wrathful Meditant to its owner's hand.

Flash
When Pivot-Fist Meditant enters, choose a creature you control. Whenever that creature is dealt damage this turn, it deals that much damage to any other target.