msem-instigator

Whenever Professor's Assistant becomes tapped, add {R}. Until end of turn, you don't lose this mana as steps and phases end.

Target player reveals their hand. You choose a nonland card from it. That player discards that card.
Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
Morph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

{1}{W}, {T}, Sacrifice Prophet of Pacifism: Prevent all damage that would be dealt to players this turn.
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.)

At the beginning of your upkeep, you gain 1 life.
Whenever one or more creatures attack you, you gain 1 life.

Choose two or four —
• Prove Worthy has lifelink and can't be countered.
• Prove Worthy deals 3 damage to target player or planeswalker.
• Prove Worthy deals 3 damage to target creature or planeswalker.
• Conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

As an additional cost to cast this spell, pay any amount of life.
Search your library for a card. If you have 10 or less life, search your library for two cards instead. Put those cards into your hand, then shuffle.

Put target nonland permanent on the bottom of its owner's library. You gain life equal to the number of poison counters its owner has.

Scry 1, then draw a card.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Destroy target tapped creature. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Put a -1/-1 counter on target creature. Purge the Harbor deals 1 damage to that creature's controller.

{G}: Exile target card from a graveyard. You gain 1 life and Purging Watchkeeper gets +1/+1 until end of turn.

Enchant creature
When Pursued Paranoia enters, scry 1.
Enchanted creature can't block.

Enchant nonland permanent
Enchanted permanent can't attack and its activated abilities can't be activated.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Rafter Stalker can't be blocked by creatures with greater power.

Flash
When Rahit's Prodigy enters, return target instant or sorcery card from your graveyard to your hand, then discard a card.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
At the beginning of your upkeep, put the top card of any of your libraries on the bottom of the archived library, then you may put any card in the archived library on top of the archived library.

[+1]: For each player, exile the top three cards of that player's library, then put one of those cards into that player's hand.
[0]: Choose target card exiled by Rahit. Until your next turn, you may play that card, and you may spend mana as though it was mana of any type to cast it.
[–7]: Target player draws seven cards.

[+1]: Each player may draw a card. For each opponent who does, put a loyalty counter on Rahit.
[–1]: Each player draws three cards, then puts two cards from their hand on top of their library in any order.
[–6]: You get an emblem with “Discard a card with mana value X: Counter target spell with mana value X or less.”

Create two 1/1 red Soldier creature tokens with haste.

Equipped creature has “Whenever this creature attacks, untap each other creature you control.”
Equip {3}

({T}: Add {R} or {G}.)
Whenever Rampant Summit becomes tapped, you lose 1 life unless you control two or more basic lands.

Target creature you control gets +1/+1 and gains hexproof until end of turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)

Equipped creature is a Flagbearer in addition to its other types.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.
Equip {5}