msem-instigator

Creatures you control dying cause abilities of that creature to trigger as though that creature entered.
{2}{W}{B}, Sacrifice another creature: Destroy target nonland permanent.

Equipped creature gets +2/+0. As long as it's a Knight, it has first strike.
Equip {1}{W}

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
When Gilded Champion becomes renowned, you may search your library for an Equipment or Aura card, reveal it, put it into your hand, then shuffle.

Noxan Altar enters tapped.
{T}: Add {W} or {B}.
{W}{B}, {T}, Tap an untapped creature you control: Create a Function token with “Lifelink.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

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}.

Vigilance
Menagerie — When Hoof Cliff Trihorn enters, if there are five or more creature types among creatures you control, you may search your library for a card named Hoof Cliff Trihorn, reveal it, put it into your hand, then shuffle.

Flying
Whenever Carrier Pigeon attacks or blocks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

Harmony — Target creature gains flying until end of turn.
When Glamorous Aerialist enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}, Sacrifice Jade Vault Reclaimer: Destroy target artifact or enchantment.

({T}: Add {B}.)
Forgotten Pit enters tapped.
Deathtouch
{2}{B}{B}: Forgotten Pit becomes a creature in addition to its other types until end of turn.

Double strike
Motley — As long as there are five or more names among nonland permanents you control, Champion of Blades has vigilance, trample, and haste.

Target creature you control deals damage equal to its power to target creature you don't control. Scry 1.

Return up to one target creature you control and up to one target creature you don't control to their owners' hands.

{X}, Exile Mysterious Coffer: Return all nonland permanents with mana value X or less to their owner's hands.

Monstrous Amalgam gets +X/+X, where X is the number of creature cards in your graveyard.
{B}, Reappropriate: Put a +1/+1 counter on Monstrous Amalgam. Activate only once each turn. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

Creatures can't attack Lord Rickard Dawson unless their controller pays 2 life or discards a card for each creature they control that's attacking him.
[+1]: Create a tapped Treasure token, then you may pay {1}. If you do, each opponent discards a card.
[+1]: You may sacrifice an artifact. When you do, Lord Rickard Dawson deals 3 damage to any target and you gain 3 life.
[–7]: Each opponent gets an emblem with “At the beginning of your end step, if it's not an extra turn, take an extra turn after this one. Target opponent controls you during that turn.”

Trample
Art of war — At the beginning of your end step, if Imperial Legion dealt damage to an opponent this turn, put two +1/+1 counters on it.

Target creature gets -3/-3 until end of turn. If you control a legendary creature, instead destroy that creature.

As Aquatic Refuge enters, you may tap an untapped creature you control. If you don't, Aquatic Refuge enters tapped.
{T}: Add {W} or {U}.

When Grave Reaper enters, if it wasn't cast from your hand, it gets +1/+1 until end of turn.
Unearth {B} ({B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

Exile any number of target artifacts and/or enchantments you control, then return them to the battlefield under your control.

Double strike
Art of war — At the beginning of your end step, if Kogane's Swordmaster dealt damage to an opponent this turn, put a +1/+1 counter on it.

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.

When Lost Crew enters or dies, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Return target nonland permanent to its owner's hand.
Reprise {2}{U} (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.)