msem-instigator

Whenever you cast an instant or sorcery spell, each opponent loses 1 life and Beast of Pestilence gets +1/+1 until end of turn.

{T}: Add {G}.
{T}: Add {G}{G}. Activate only if you control an Elemental.

Target creature you control fights target creature you don't control.

Target creature you control gains indestructible until end of turn if it's embattled. Then it fights target creature you don't control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Look at the top two cards of your library. Put one of them into your hand, then submerge the other. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Bloodprice {2}{B}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)
Return target creature card from your graveyard to your hand. If you cast this spell for its bloodprice, return that card to the battlefield instead.

Draw a card, then reveal any number of creature or land cards from your hand. You gain that much life.

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Prevent all combat damage that would be dealt this turn. You gain 1 life for each creature you control.

{T}: Add one mana of any color.
{2}, {T}: Put a lore counter on a Saga you control.

Counter target spell unless its controller pays {1} or if it has the same name as a permanent or a card in a graveyard.

When Beguiling Witch enters, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)
Whenever another creature dies, each opponent mills X cards, where X is Beguiling Witch's power.

Augmented — When Behavioral Specialist enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, create a 1/1 blue Elemental creature token with flying.
Whenever one or more creatures you control deal combat damage to an opponent, you may draw a card. If you do, discard a card.

Destroy target creature.
Civilized — You gain 3 life if you control an artifact, a creature, and an enchantment.

Enchant creature
Enchanted creature gets +1/+1 and has vigilance.
{2}{G}: Return Behold the Horizon from your graveyard to your hand.

Enchant creature
Enchanted creature has base power and toughness 1/1 and is a Frog in addition to its other types.
When enchanted creature deals damage to a player, sacrifice Belittle.

When Bellani Mystic enters, target player mills two cards.

Whenever another creature you control dies, put a +1/+1 counter on Belligerent Mob.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Destroy target artifact or enchantment.
Draw a card.

Mill four cards, then you may return a creature or planeswalker card from your graveyard to your hand.
As long as Beneath the Zhedina is in your graveyard, other cards in your graveyard can't be the target of spells or abilities your opponents control.

When Benthic Shipcrasher enters, scry 3.

{T}: Until end of turn, target land is every basic land type in addition to its other types and its name becomes Morphic Sea.

Armed — Beragnian Blacksmith can't attack unless it's equipped.
When Beragnian Blacksmith enters, you may pay {2}. If you do, arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to this creature.)