msem-instigator

When Blighting Ooze enters, put a -1/-1 counter on each of up to X target creatures.
As long as Blighting Ooze is on the battlefield, it has all activated abilities of each creature with a -1/-1 counter on it.

Exile the bottom card of your library, a card from your hand, and a card you own from outside the game. Put them in a face down pile, shuffle that pile, then manifest those cards. (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.)

Choose one —
• Welcome to the Ashmouth deals twice X damage to target creature or planeswalker.
• Welcome to the Ashmouth deals X damage to each creature and each planeswalker.
Flashback {X}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Put target nonland permanent on top of its owner's library. If you control a Wizard, you may put that permanent on the bottom of its owner's library instead.

Menace
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Jaded Guardian. It loses this ability and gains “Whenever this creature attacks, defending player sacrifices two permanents.”

Hexproof
Mist-Valley Ancient enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Destroy target noncreature permanent.
Recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Whenever you attack, you may discard a card. If you do, exile the top two cards of your library. You may play one of them this turn.
Once each turn, when a card leaves your graveyard, you may add {C}{R}.

When Vicious Shamshir enters, you may attach it to target creature you control. If you do, target creature can't block this turn.
Equipped creature gets +2/+0.
Equip {3}

[+2]: Exile any number of target artifacts and/or enchantments you control, then return them to the battlefield under your control. You may draw that many cards.
[–4]: Search your library for an enchantment card, put that card onto the battlefield, then shuffle.
[–12]: Put any number of permanent cards you own from outside the game onto the battlefield tapped.

Create three 1/1 green Saproling creature tokens.

Whenever a nontoken creature enters under your control, create a Field land token with “{T}, Sacrifice this land: Add one mana of any color.”
Whenever a nontoken land enters under your control, create a 1/1 white Peasant creature token.

Flying
At the beginning of your upkeep, if you have at least two more cards in hand than any opponent, scry 1.

Choose two —
• Counter target spell unless its controller pays {6}.
• Target player draws two cards, then discards a card.
• Creatures target player doesn't control get -3/-0 until end of turn.
• Exile up to two target creatures, then return those cards to the battlefield under their owners' control.

Search your library for up to two land cards with basic land types, put them onto the battlefield, then shuffle. Sacrifice two lands at the beginning of the next end step.

Target creature you control gets +5/+5 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, destroy up to one target artifact.

Destroy target artifact.
Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.)

Prowess
When Magus Aspirant enters, you may search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Players skip their untap steps during extra turns.

Choose one or more —
• The Sun Rises deals 2 damage to any target.
• The Sun Rises deals 7 damage to target creature you control.

({T}: Add {R}.)
As Highland Dunes enters, you may pay 1 life. If you don't, Highland Dunes enters tapped.

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

Whenever a creature enters without counters during your next turn, you may put two +1/+1 counters on it. (Then exile this card. You may cast the creature later from exile.)

Bestial Mob's power and toughness are each equal to the number of creatures you control.
Whenever Bestial Mob deals combat damage to a player, destroy target creature with toughness less than Bestial Mob's power.

Enchant opponent
The first time enchanted player chooses targets each turn, reselect each of those targets at random.