msem-instigator

When Powercell Engineer enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”

Precursor Sanctum enters tapped. When it does, look at the top three cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
{T}: Add {C}.
{4}, {T}: You may play the exiled card without paying its mana cost. Activate only as a sorcery.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever Primal Ruffian attacks, if it has a +1/+1 counter on it, other creatures you control get +1/+1 until end of turn. (If it had no counters on it when it attacked, this ability does not trigger.)

Flash
When Prismatic Champion enters, create a white Aura enchantment token named Sunward attached to target creature. The token has enchant creature and “Enchanted creature has protection from creatures.”

When Prodigious Telemancer enters, you may draw a card, then discard a card.
Whenever you cast an instant or sorcery spell, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

You may play Promethean Grotto from your graveyard.
{T}: Add {C}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Whenever equipped creature deals combat damage to a player, put a +1/+1 counter on it, then proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)
Equip {2}

At the beginning of your upkeep, you may pay 2 life. When you do, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

Flying
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Other creatures you control get +1/+1 for each +1/+1 counter on Protector of the League.

Choose one —
• Purging Light deals 3 damage to target attacking or blocking creature. If that creature would die this turn, exile it instead.
• Exile target enchantment.

When Pyroclastic Maw enters, destroy target land. If that land was nonbasic, Pyroclastic Maw gains haste until end of turn.

Choose one —
• Target creature gets +4/+2 until end of turn.
• Pyromantic Expertise deals 4 damage to target creature or planeswalker.

When Quandary Seer enters, target player mills three cards. You shuffle up to three cards from your graveyard into your library.

Whenever you tap a land for mana, add an additional one mana of any color.
{8}{G}{G}: Creatures you control get +2/+2 and gain trample until end of turn.

Destroy target creature or planeswalker. Create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

({T}: Add {W} or {U}.)
Rainsculpted Gorge enters tapped.
{1}, {T}: Add {W}{W} or {U}{U}.

Ravenous Hydra enters with X +1/+1 counters on it.
Whenever Ravenous Hydra deals combat damage, proliferate. (You choose any number of permanents and/or players with counters on them, then give each another kind of a counter already there.)

{T}: Add {C}.
{2}, {T}: Target creature gains haste until end of turn.

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Choose one or both —
• Each player shuffles their hand and graveyard into their library, then draws seven cards.
• Each player may put a permanent card from their hand onto the battlefield.
Exile Reality Rewoven.

Exile the top card of your library and up to one target permanent card from your graveyard. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Whenever Reclamation Grovesculptor enters or attacks, put a growth counter on target noncreature permanent. It becomes a colorless Forest land and loses all other card types and land types.

Flash
{U}, Return another creature you control to its owner's hand: Reclusive Archmage can't be blocked this turn and gains hexproof until end of turn. Activate only once each turn.

This spell costs {1} less to cast for each artifact you control.
Search your library for an artifact creature card with mana value X or less, put it onto the battlefield, then shuffle.

When Relentless Pathcutter enters, create a green Aura enchantment token named Enmity attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+0 and has trample.”
When Relentless Pathcutter dies, return it to its owner's hand.