msem-instigator

As an additional cost to cast this spell, sacrifice a land.
Create a 6/6 red Wurm creature token with “This creature can't be blocked by creatures with flying.”

Put a +1/+1 counter on target creature. It can't be blocked this turn.(Cast a copy of this spell once while this creature is on the battlefield.)

Equipped creature has “{T}: This creature deals damage equal to its power to any target.”
Equip {4}

Exchange control of two target creatures. If an opponent gained control of a Monk you controlled this way, return that creature to its owner's hand.

Target player mills three cards for each poison counter they have.

When Memories Rewound enters, you may put target card from your graveyard on top of your library.
{1}: Put target card from your graveyard on the bottom of your library. Activate only once during each of your turns.

Ferocious Flame deals 2 damage to any target. If you control a creature with power 4 or greater, it deals 4 damage instead.

Landfall — Whenever a land you control enters, Convoy's Companion gets +1/+1 until end of turn. If that land was a Desert, put a +1/+1 counter on it instead.

Dominance — At the beginning of combat on your turn, if you control the creature with the greatest power or tied for the greatest power, you may pay {R}. If you do, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Whenever Babbling Experiment or another creature you control enters, target player mills two cards.

{1}, {T}: Draw a card, then exile a card from your hand face down until Cluttered Study leaves the battlefield. (It returns to your hand.)
{3}, {T}: Shuffle Cluttered Study into its owner's library.

Landfall — Whenever a land you control enters, add {G}.
{3}{G}: Target creature you control gets +2/+2 until end of turn.

Enchant player
When Curse of the Vein enters, create a 1/1 black and red Vampire creature token with menace.
Whenever enchanted player is attacked, Curse of the Vein deals 1 damage to them.

You may pay {1}{G} and tap an untapped Soldier you control rather than pay this spell's mana cost.
Put two +1/+1 counters on target creature. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

First strike
When Frontline Descender enters, you may salvage an instant or sorcery card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Target opponent sacrifices a creature or planeswalker.
3 | That player also sacrifices an artifact or enchantment.

Menace
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Jaded Guardian. It loses this ability and gains “Whenever this creature attacks, defending player sacrifices two permanents.”

Enchant creature
Creatures blocking or blocked by enchanted creature have lifelink.

Enchant creature
Enchanted creature gets +2/+2 and has flying.
When enchanted creature dies, draw a card.

Whenever another creature you control dies, target player loses 1 life and you gain 1 life.
{1}{B}, Sacrifice a creature: Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Menace
Whenever Coirchanh deals combat damage to a player, return up to one target creature card with toughness 4 or greater from your graveyard to the battlefield with a finality counter on it.
{1}{G}: This creature gets +0/+2 until end of turn.

When Dawson's Loot enters, mill two cards, then draw a card.
{1}, {T}, Sacrifice Dawson's Loot: Add one mana of any color.

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Indestructible (Damage and effects that say “destroy” don't destroy this creature.)

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.