msem-instigator

Whenever you cast a nonblue spell, create a 1/0 blue Horse Nymph creature token.
Horses get +1/+1 and have flying.

Primal {R} (During your turn, you may cast this spell for {R} instead of playing a land.)
Target creature gets +4/+0 and gains trample until end of turn.

Equipped creature has hexproof and can't be blocked.
Equip {1}
Whenever Ring of Souls becomes attached to a creature, an opponent of your choice may create a 2/2 black Spirit creature token.

Target creature gets -4/-4 until end of turn. When it dies this turn, create two 1/1 black Worm creature tokens.

At the beginning of your upkeep, if an opponent has more life than you, create a 4/4 red Elemental creature token with haste and “Creatures blocking this creature have winnow.” (Damage dealt to a creature with winnow causes its controller to lose that much life.)

When Ritesinger Shaman dies, each player discards a card.

River's Wrath deals 2 damage to any target. If you've been dealt damage this turn, River's Wrath deals 4 damage instead.

Search your library for up to two basic land cards and put them onto the battlefield tapped, then shuffle.
Fuse (You may cast one or both halves of this card from your hand.)

Create a number of 3/3 green Elemental creature tokens equal to the number of differently named lands you control.
Fuse (You may cast one or both halves of this card from your hand.)

Defender
As long as you control an enchantment, Rooted Cavalier has vigilance and can attack as though it didn't have defender.

{1}{U}, {T}, Discard a card: Reveal the top card of your library. Counter target spell unless its controller pays {X}, where X is the mana value of that card.

{T}, Sacrifice Rootshambler: Untap all basic lands you control.

{6}: Create a 1/1 black Worm creature token.

{2}{G}: Rotted Kalak gains indestructible until end of turn.
Revive {3}{B} ({3}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

When Rotting Sunseeker dies, return target creature card with power 2 or less from your graveyard to your hand.

{T}: Add {B} or {G}. You lose 1 life.

Each Rogue you control can't be blocked by creatures with greater power than it.
Whenever a Rogue deals combat damage to a player, gain control of target nonland permanent that player controls unless that player pays {1}.

Enchant creature
Enchanted creature gets -3/-3.

{T}: Add {C}.
{1}, {T}: Transform Ruined Theater.

Enchant creature
Enchanted creature gets +3/+0 and has menace.
Whenever enchanted creature deals combat damage to a player, discard a card, then draw a card.

({T}: Add {R} or {W}.)
As Ruptured Citadel enters the battlefield, you may pay {1}. If you don't, Ruptured Citadel enters the battlefield tapped.

({T}: Add {W} or {B}.)
As Ruptured Expanse enters the battlefield, you may pay {1}. If you don't, Ruptured Expanse enters the battlefield tapped.

({T}: Add {U} or {R}.)
As Ruptured Falls enters the battlefield, you may pay {1}. If you don't, Ruptured Falls enters the battlefield tapped.

({T}: Add {B} or {R}.)
As Ruptured Flats enters the battlefield, you may pay {1}. If you don't, Ruptured Flats enters the battlefield tapped.

({T}: Add {U} or {B}.)
As Ruptured Grotto enters the battlefield, you may pay {1}. If you don't, Ruptured Grotto enters the battlefield tapped.