msem-instigator

Manifest all cards from all players' hands. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
If you would gain life, you may put a +1/+1 counter on this creature instead.
When this creature has toughness 20 or greater, you win the game.

Haste
When Speaker of the Iris enters the battlefield, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
Other creatures you control have haste.

When Specialized Training Dummy enters the battlefield, choose a card name.
Other creatures you control with the chosen name get +1/+1.

Rouse 4. Sacrifice a creature at the beginning of the next end step. (Distribute four +1/+1 counters among permanents you control. If they aren't creatures, tap them and they become 0/0 creatures in addition to their other types.)

Flash
Flying
When Spectrum Archmage enters the battlefield, return target spell to its owner's hand, then abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

When Speed Reader enters the battlefield, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Add {R}{R}.

When Spellslinger's Gauntlet enters the battlefield, exile an instant or sorcery card with mana value 3 or less from your hand.
Whenever equipped creature attacks, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {3}

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.)
Remove a +1/+1 counter from Spellsword Elite: The next noncreature spell you cast this turn costs {1} less to cast.

Defender, 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.)
Remove a +1/+1 counter from Spellwork Bulwark: It loses defender and gains hexproof and indestructible until end of turn.

When Spirit of Autumn enters the battlefield, nourish X, where X is the number of creatures you control. (To nourish X, either put X +1/+1 counters on this creature or create X 1/1 white Citizen creature tokens.)

Vigilance, reach
{T}: Splitshaft Deadeye deals damage equal to its power to target creature with flying.

Draw a card. Scry 2.
Orchestrate {U} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Target creature gains haste until end of turn. That creature attacks or blocks this turn if able.

Return target spell to its owner's hand. Its controller can't cast spells this turn. (Spells cast before this resolves are unaffected.)

When Stalwart Physicker enters the battlefield, you may remove a -1/-1 counter from target creature.

Whenever Starfall Instructor attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Each opponent loses 2 life.

{T}: Add {C}.
{T}, Pay 1 life: Add {G}.
{G}, {T}: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{B}, {T}: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add {W}.
{W}, {T}: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add {U}.
{U}, {T}: Add one mana of any color.

{T}: Add {C}.
{T}, Pay 1 life: Add {R}.
{R}, {T}: Add one mana of any color.

Each player chooses up to half the creatures they control, then sacrifices the rest.

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Enchant creature
Enchanted creature gets +2/+2.
Sacrifice Steady Reminiscence: Enchanted creature gains indestructible until end of turn.