msem-instigator

Menace
When Zygos's Decimators enters, put a number of +1/+1 counters on it equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Zygos, Underworld Scourge's power and toughness are each equal to the number of cards you own in exile and in your graveyard.
Spells you cast have “As an additional cost to cast this spell, you may exile any number of cards from your graveyard. This spell costs {1} less to cast for each card exiled this way.”

Destroy target creature. End of the Road deals damage equal to that creature's power to that creature's controller or a planeswalker that player controls.

Choose two or four —
• Prove Worthy has lifelink and can't be countered.
• Prove Worthy deals 3 damage to target player or planeswalker.
• Prove Worthy deals 3 damage to target creature or planeswalker.
• Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Choose two —
• Each opponent sacrifices a creature with mana value 3 or less.
• Each opponent sacrifices an enchantment with mana value 3 or less.
• Exile each opponent's graveyard.
• You gain 3 life.

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Tap target creature and put two stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

You may play an additional land this turn.
Draw a card.

Menace
Whenever one or more creature cards leave your graveyard, put a +1/+1 counter on Mausoleum Resident. It gains lifelink until end of turn.

Unstoppable Slaughter deals 1 damage to each creature and each player. Whenever a creature dealt damage by Unstoppable Slaughter this turn dies this turn, repeat that process.

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.

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Wild Lifescale attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Search your library for a creature card with mana value 3 or less, put it onto the battlefield, then shuffle. It gains haste until end of turn. Return it to your hand at the beginning of the end step.

As long as it's your turn, Ameret is a 4/4 Angel creature with flying, haste, indestructible, and “Whenever Ameret attacks, attach any number of Equipment you control to them.”
[+2]: Create two 1/1 red and white Cleric creature tokens with lifelink.
[–3]: Ameret deals 4 damage to target creature or planeswalker. You gain 4 life.
[–4]: For each creature you control, create a Weapon token and attach it to that creature. (It's an Equipment artifact with equip {2} and “Equipped creature gets +1/+1.”)

As an additional cost to cast this spell, tap an untapped Warlock you control.
Search your library for a card and put it into your hand or graveyard, then shuffle.

Spells your opponents cast cost {1} more to cast.
Spells you cast cost {1} less to cast.

Deception {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible.
[+1]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.

At the beginning of your end step, you may mill two cards. If you do, you gain 2 life.
[+1]: You may discard a card. If you do, draw a card.
[–2]: Exile up to six cards from your graveyard. Create a 1/1 red and green Spirit creature token for each two cards exiled this way.
[–6]: You may cast a card from your hand or graveyard without paying its mana cost. If it has {X} in its mana cost, X is 6.

Noncreature spells your opponents cast cost {1} more to cast.
Unveil {2}{W}{U} ({2}{W}{U}: Transform this. Unveil only as a sorcery.)

[+1]: Create three 1/1 white Warrior creature tokens. They gain haste.
[0]: Until end of turn, each creature and planeswalker you control becomes a 3/3 Warrior creature and gains indestructible. (Permanents don't lose loyalty while they're not a planeswalker.)
[–2]: Choose tapped or untapped. Seto San deals 3 damage to each creature with the chosen attribute.

{T}: Add {C}.
{T}: Add one mana of any color among planeswalkers you control.
{1}, {T}: Put a loyalty counter on target planeswalker that activated a loyalty ability this turn.

Instant and sorcery spells you control have rerun. (Exile the spell as it resolves if you cast it from your hand. Whenever a creature you control dies, you may cast that card from exile without paying its mana cost.)

Abandoned Chamber enters with X story counters on it.
{3}, {T}, Remove all story counters from Abandoned Chamber and exile it: Return a card from your graveyard to your hand for each counter removed this way.

As long as you control four or more differently named lands, creatures you control get +1/+1.
As long as you control a land named Far-Off Lands, creatures you control get +1/+1.

Archive X, where X is the number of planeswalkers you control. (As this enters, shuffle the top X cards of your main library into a new face up library. Sacrifice this when the archived library is empty.)
Remove a loyalty counter from a planeswalker you control: Draw a card from the archived library.

You may spend mana as though it were mana of any color to cast planeswalker spells.
[–1]: Put a -1/-1 counter on target tapped creature.
[–2]: You gain 2 life for each tapped creature your opponents control.
[–3]: Destroy all creatures that attacked a planeswalker you controlled since your last turn.