msem-instigator

I, II — Each opponent loses 2 life and you gain 2 life.
Discovery — At the beginning of your end step, you draw a card and you lose 2 life.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever a creature deals combat damage to a player, if it was encouraged by Unbeholden Navigator this turn, draw a card.

Assault {X}{R}{R} (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.)
Other Elementals you control get +1/+0.
When Unbound Annihilus assaults, create X 1/1 red Elemental creature tokens that are tapped and attacking.

At the beginning of each opponent's upkeep, that player may discard their hand. If the player does, sacrifice Under the Gun. Otherwise, put a bullet counter on Under the Gun, then that player loses life equal to the number of bullet counters on it.

When Urn of Heroes enters, you may search your library for a legendary card, put that card into your graveyard, then shuffle.
{T}: Add {C}.

Haste
When Urud Stingswoop enters, it gains flying until end of turn.

Assault {1}{R} (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 Urudi Warlord assaults, it gains first strike until end of turn.

Valeron Vanguard can't be blocked by 1/1 creatures.

When Varakna Wurm enters, it deals X damage to target creature an opponent controls, where X is the total number of creature cards you own in exile and in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

Flash
Embellish {5}{U} (If you cast this spell for {5}{U}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
Whenever Vectis Entrancer or another artifact you control enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever a creature deals combat damage to a player, if it was encouraged by Veteran Horncaptain this turn, exile the top three cards of your library. You may put a permanent card from among them onto the battlefield.

When Viashino Glutton enters, you may have it consume. If you do, create two 1/1 red Goblin creature tokens. (To consume, sacrifice another creature or exile a creature card from your graveyard.)

Return target spell to its owner's hand. If there are three or more colors among permanents you control, you may counter that spell instead.

Exile the top two cards of your library and put a blood counter on each of them. Until the end of your next turn, you may play cards you own in exile with blood counters on them.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

At the beginning of your upkeep, look at the top card of your library. If it's an artifact card, you may reveal it and put it into your hand.

Vitalhydra enters with twice X +1/+1 counters on it.
Each other creature you control enters with a number of additional +1/+1 counters on it equal to the number of +1/+1 counters on Vitalhydra.

Vithian Arcanist gets +2/+0 and has haste as long as you've cast an instant or sorcery spell this turn.
When Vithian Arcanist enters, add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.

When Volcano Elemental dies, it deals 2 damage to any target.

Assault {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.)
Whenever a creature you control assaults, it gains indestructible until end of turn.

If you would gain life this turn, you gain twice that much life instead.
Draw a card.

Flying
Cycling {2} ({2}, Discard this card: Draw a card.)

When Wealthy Merchants enters, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

{T}: Add {C}.
{3}, {T}: Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Trample
World Tender's power and toughness are each equal to twice the number of differently named lands you control.

At the beginning of your upkeep, if there are three or more colors among creatures you control, you gain 2 life and draw a card.