msem-instigator

{1}{R}, {T}, Sacrifice a land: Create a colorless Desert land token with “{T}: Add {C}.”
{1}{R}, {T}: Sacrifice a Desert: Destroy up to two target lands.

Flying
Whenever you attack with three or more creatures, exile the top card of your library. You may play that card until you exile another card with Zarthane, Scourge of Galdurheim.
{2}{B/R}: Target creature gets +1/+0 and gains menace until end of turn. Activate only as a sorcery.

{1}, {T}, Move a -1/-1 counter from another creature onto Zealous Bloodletter: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flying
When Zhu Long enters the battlefield, if {W}{U}{B}{R}{G} was spent to cast it, untap up to five target lands.
Once during each of your turns, when you cast an instant or sorcery spell, if no more than one mana of each color was spent to cast it, you may copy it. You may choose new targets for the copy.

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
[+1]: Create a 2/2 blue Elemental Illusion creature token with flying and “Whenever this becomes the target of a spell, sacrifice it.”
[–2]: Return up to one other target nonland permanent to its owner's hand. Draw a card.

Whenever an enchantment enters the battlefield under your control or Zoulev Ritualist becomes enspirited, draw a card.

Menace
When Zygos's Decimators enters the battlefield, 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.”