msem-instigator

Trample, prowess
You may exert Wartorn Veteran as it attacks. When you do, double its power until end of turn. (An exerted creature won't untap during your next untap step.)

Whenever Gravelocked Seeker blocks, return target creature card from your graveyard to the battlefield blocking a creature that's attacking you (even if that block would be illegal).

Defender
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{T}: Student of Lightning deals damage equal to its power to target player.

First mate—Your starting deck contains one or more cards of exactly each color and each color pair. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
During each of your turns, you may cast a card of each color from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead.

Tap target creature. Prevent all combat damage that creature would deal this turn. It doesn't untap during its controller's next untap step.

{T}: Add {C}.
At the beginning of each end step, if you control five or more Snake creatures, transform Aghavaan's Wound.

Target player mills four cards, then mills an additional four cards for each Curse attached to them.

Enchant creature
Enchanted creature gets -3/-3.

Vigilance, haste
All creatures able to block Jormir, Who Encircles All do so.
Jormir, Who Encircles All can block any number of creatures.

Whenever you cast an instant, sorcery, or Curse spell, Stromkirk Sangromancer deals 1 damage to each opponent.

Flash

This spell can't be countered.
Exile your library, then shuffle Revisionary Studies, your graveyard, and your hand into your library. Draw five cards.

Whenever an Army you control dies, if it wasn't sacrificed, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Vigilance, lifelink

Hollowghast, the Iron Phantom enters with three +1/+1 counters on it.
If damage would be dealt to Hollowghast, prevent that damage. Remove a +1/+1 counter from Hollowghast.

Tranquil Cove enters tapped.
When Tranquil Cove enters, you gain 1 life.
{T}: Add {W} or {U}.

Put two +1/+1 or loyalty counters on target creature or planeswalker. It gains lifelink until end of turn.

Flash
Ocean's Edge Kraken enters with a hexproof counter on it.
{6}{U}{U}, Remove a hexproof counter from Ocean's Edge Kraken: Return all other creatures to their owners' hands.

Flying, vigilance
When Silksoul Celestial enters, search your library for an enchantment or Aurashaper card, reveal it, put it into your hand, then shuffle.
When Silksoul Celestial dies, you may put an enchantment or Aurashaper card from your hand or graveyard onto the battlefield.

Wildrune Thicket enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Destroy target creature that's not enchanted and isn't an enchantment.

Enchant creature
Enchanted creature gets +2/+1 and is a black Zombie in addition to its other colors and types.

Whenever Bazaar Informant deals combat damage to a player, reveal the top card of that player's library. If it's a nonland card, put a +1/+1 counter on Bazaar Informant, then that player puts that card into their graveyard.

When Brand New Species enters, create a tapped 3/2 green Horror creature token.
Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on up to one target Horror you control.

({T}: Add {U}.)
Inundated Sanctuary enters tapped with two sanctum counters on it.
{T}, Remove a sanctum counter from Inundated Sanctuary: Add {W} or {B}.