msem-instigator

Whenever Babbling Experiment or another creature you control enters, target player mills two cards.

First strike (This creature deals combat damage before creatures without first strike.)
Other Soldier creatures you control get +1/+1 and have first strike.
{3}{W}: Create a 1/1 white Soldier creature token.

Flash
Once each turn, you may cast a spell without paying its mana cost. If you do, at the beginning of your next upkeep, you lose the game unless you pay that spell's mana cost.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
{1}{G}: Bastion Ranger gains reach and deathtouch until end of turn.

Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
Whenever a creature you control becomes renowned, draw a card.

Battalion — Whenever Battleborn Brute and at least two other creatures attack, Battleborn Brute gets +2/+2 until end of turn. Untap it.

Concord — When Bazaar Equestrian enters, if there are four or more card types among permanents you control, you gain 4 life.

If you would catalyze, catalyze twice instead. (The next spell you cast this turn costs {1} less to cast.)
You may pay an additional {2} as you cast a spell. If you do, reveal the bottom card of your library. You may put it into your graveyard or on top of your library.

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

When Benthic Alchemist enters, draw a card, then discard a card, then mill a card.
Whenever you cast an instant or sorcery spell, create a 1/1 colorless Elemental creature token. It gains haste until end of turn.

When Benthic Tidebreaker enters, reveal the top card of each player's library and exile one of those cards. You may play that card for as long as it remains exiled, and you may spend blue mana as though it were mana of any color to cast it.
Evoke {1}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Armed — Whenever Beragnian Intimidator attacks, if it's equipped, target creature can't block this turn.

At the beginning of your upkeep, mill a card.
Whenever a creature card is put into your graveyard from anywhere, if that card has flying, you may put a flying counter on Berylscale Alaj. Repeat this process for first strike, double strike, deathtouch, hexproof, lifelink, menace, reach, trample, and vigilance.

Bjarndyr Bruiser gets +2/+2 as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Trample
Revive {5}{B} ({5}{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.)

Blighted Unicorn can't block.
Ride {3}{B} ({3}{B}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

{4}{R}: Blind Tunneler gets +3/+0 until end of turn.

Whenever Blood Constrictor becomes blocked by a creature, you gain life equal to that creature's toughness.

Sacrifice another creature: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Bloodline Zealot gets +2/+0 and has menace as long as you've sacrificed a permanent this turn.

When Bloodpact Collector enters, destroy target creature an opponent controls that was dealt damage this turn or has a -1/-1 counter on it.

Discard a card: Bloodshot Berserker gets +1/-1 until end of turn. Any player may activate this ability.

Trample
Bloodthirsty Berserkers can't be blocked by more than one creature.

At the beginning of your first main phase, add an amount of {G} equal to Bloomhorn's power.