msem-instigator

{U}, Discard a card: Exile target instant or sorcery card from your graveyard. If you do, copy it. You may cast the copy.
{B}, Discard a card: Exile target creature card from your graveyard and pay its mana cost. If you do, create a token that's a copy of it. Activate only as a sorcery.

At the beginning of your upkeep, you may put a card from your graveyard on the bottom of your library. If you do, you gain 2 life.
{2}, Sacrifice Rune of Rejuvenation: Draw a card.

Bulwark — {2}{G}: Stronghold Recruit gets +2/+2 until end of turn. Activate only once each turn and only if you control a creature with toughness 4 or greater.

Heroic — Whenever you cast a spell that targets Meletis Stargazer, scry 2.
{T}: Look at the top card of your library. If it's a permanent card with mana value 3 or less, you may reveal it and put it into your hand.

Double strike
Attain {3}{R} ({3}{R}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Enchant creature
When Vampiric Rise enters, fateseal 2. (Look at the top two cards of an opponent's library, then put any number on the bottom and the rest on top in any order.)
Enchanted creature gets +1/+0 and has flying.

Untap target creature. It gets +2/+2 and gains hexproof until end of turn.

Target creature gets +3/+3 until end of turn and must be blocked this turn if able.
Showcase {3}{G}{G} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Whenever an artifact or enchantment you control enters, Armament Scavenger gets +1/+0 and gains trample until end of turn.

When Matron of Machines dies, put a +1/+1 counter on up to one target creature.
{3}{W}, Exile Matron of Machines from your graveyard: Create two 1/1 colorless Construct artifact creature tokens. Activate only as a sorcery.

As an additional cost to cast this spell, pay {2} or reveal an instant or sorcery card from your hand.

Flying
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

Haste
Augmented — When Attuned Lifeform enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on each creature you control. They gain vigilance until end of turn.

Other Goblins you control get +1/+0 and have menace.

Until end of turn, target creature gets +2/+0 and gains “When this creature dies, return it to the battlefield tapped under your control.”

When Driftpicker enters, you may return another non-Crab creature you control to its owner's hand. If you do, create two 1/1 white Bird creature tokens with flying.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Morass: Choose a basic land type other than Swamp. Create a colorless land token that's a Swamp and the chosen basic land type. Activate only during your upkeep.

Flash
Flying
When Mellan enters, exile up to one other target nonland permanent with mana value equal to or less than the number of creatures you control with flying until Mellan leaves the battlefield.

When Elemental Loremaster enters, return an instant or sorcery card at random from your graveyard to your hand.

When Smokeweaver Initiate dies, draw a card.

{T}: Add {W} or {U}. You lose 1 life unless you have less life than an opponent.

Choose one —
• Target opponent discards a card.
• Amosis Charm deals 1 damage to any target and you gain 1 life.

Whenever you cast a white spell, create a 1/1 white Nymph creature token.

{T}: Add {C}.
Shrine of the World-Shepherd's power and toughness are each equal to the number of differently named lands you control.
{3}{G}: Shrine of the World-Shepherd becomes a Beast creature in addition to its other types until end of turn.

Subway Shambler can't be blocked by creatures with lesser power.
At the beginning of each end step, if you're horrific, put a +1/+1 counter on Subway Shambler. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)