msem-instigator

{1}{B}, {T}: Target creature gets +2/+2 and gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)
{3}{B}{B}, {T}: Target creature gets -2/-2 and gains winnow until end of turn.

Vision (Whenever this or another creature enters the battlefield under your control, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Blind Soulcaller envisions an instant or sorcery card, you may tap target permanent.

Prowess

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

Advance {1}{R} (Cast this for {1}{R} to advance it as it enters. {1}{R}: Advance this as a sorcery.)
Whenever Blitz Breaker advances, its power becomes equal to the amount of noncombat damage that's been dealt to your opponents this turn. (This effect lasts indefinitely.)

Flying
Whenever Blizzard Dragon attacks, tap an artifact, a creature, and a land defending player controls. They don't untap during their controller's next untap step.
At the beginning of each opponent's upkeep, that player sacrifices a tapped permanent.

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Whenever an attacking creature you or a teammate controls dies, you lose 1 life and draw a card.

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

As an additional cost to cast this spell, sacrifice any number of creatures.
Target player loses 2 life for each creature sacrificed to cast Blood Lashing.

Draw a card for each creature that died this turn.

Exile up to three target cards from a single graveyard. You gain 3 life.

At the beginning of your upkeep, each player sacrifices a nonbasic land.

As long as you've gained life this turn, Bloodied Outcast gets +1/+0 and has lifelink.
As long as an opponent has lost life this turn, Bloodied Outcast gets +0/+1 and has deathtouch.

Bloodleaf Butcher gets +1/+0 and has deathtouch as long as five or more cards are in your graveyard.

{T}: Choose a color of a card in your graveyard. Add one mana of that color.

Deathtouch

{G}, {T}: Put a +1/+1 counter on Bloodleaf Tracker for each creature that entered the battlefield this turn.

Target creature gets +1/+1 until end of turn for each card in your graveyard.

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

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)

({T}: Add {R}.)
Bloodriver enters the battlefield tapped.
When Bloodriver enters the battlefield, target creature you control gains haste until end of turn.

This spell costs {1} less to cast for each creature that attacked this turn.

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

Flash
This spell costs {2} less to cast if five or more cards are in your graveyard.