msem-instigator

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, target player discards a card.

{T}: Add {C}.
{2}, {T}: Draw a card. Activate only if you have no cards in hand.

Flying
At the beginning of each combat, target opponent may give themselves a poison counter. If they don't, Tower of Sorrows gets +3/+0 until end of turn.

Vigilance, reach
When this creature transforms into Towering Alpha, return target card from your graveyard to your hand.
At the beginning of your end step, if Towering Alpha didn't attack this turn, transform it.

Towering Boughs enters tapped.
{T}: Add {R} or {G}.
{3}{R}{G}: Until end of turn, Towering Boughs becomes a 6/6 red and green Treefolk creature with with trample and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Trample

Reach
Assault {5}{G}{G}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Towering Hydraffe assaults, create a token that's a copy of it.

Reach
Towering Silkweaver can block an additional creature each combat.

Trample
At the beginning of your upkeep, return another creature you control to its owner's hand.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Towering Wickerman can't be blocked by creatures with power 2 or less.
Whenever a creature merges with Towering Wickerman, put two +1/+1 counters on it.

{1}{W}, Sacrifice Town Elder: Return target artifact or enchantment card from your graveyard to your hand.

Deathtouch
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

Toxic Jungle enters tapped unless you have 15 or less life.
{T}: Add {B} or {G}.

Deathtouch

Whenever Toxic Lurker attacks, you may have target creature defending player controls get -2/-1 until end of turn.

Whenever Toxic Miscreant deals combat damage to a player, that player discards a card.

As Toxic Spring enters, you may tap an untapped creature you control. If you don't, Toxic Spring enters tapped.
{T}: Add {U} or {B}.

Enchant creature you control
Whenever a land you control enters, put a +1/+1 counter on enchanted creature.
{3}{G}, Sacrifice Trace the Oasis: Draw cards equal to enchanted creature's power.

Equipped creature gets +0/+2.
When equipped creature dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Equip {1}

Enchant creature
Enchanted creature has hexproof.
{U}: Enchanted creature can't be blocked by target creature this turn.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Tracker of Wild Places envisions a creature card, you may untap a permanent you control.

Tracking Party enters with a +1/+1 counter on it.
{T}, Remove a +1/+1 counter from Tracking Party and exert it: Destroy target artifact or enchantment. (An exerted creature won't untap during your next untap step.)

Flash
When Trade Route Bandit enters, you may have each player draw two cards.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)
Whenever Trading Traitor deals combat damage to a player, you lose life equal to the number of unblocked attacking creatures you control and draw that many cards.

I, II — Mill two cards. You gain 2 life. (Put the top two cards of your library into your graveyard.)
Discovery — During each of your turns, you may cast a permanent spell from your graveyard.