msem-instigator

Spells you cast from anywhere other than your hand can't be countered.
Whenever an opponent casts a spell with the same name as a card they own in exile or in their graveyard, you may draw a card.

Return target instant or sorcery card from your graveyard to your hand.

{T}: Each of two other target permanents you control that share a card type become a copy of the other until end of turn.

Choose one or both —
• Tap target creature.
• Untap target creature.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Art of war — At the beginning of your end step, if Kuryu Swordsman dealt damage to an opponent this turn, you may have Kuryu Swordsman fight target creature you don't control. (Each deals damage equal to its power to the other.)

Whenever Ensnaring Possessor attacks, you may tap or untap target permanent.
{1}{U}, {T}: Until end of turn, target creature gets +1/+1 and gains “Whenever this creature attacks, you may tap or untap target permanent.” Activate only as a sorcery.

Exile target artifact or enchantment. If its mana value is 3 or less, draw a card.

Enchant creature
Enchanted creature gets +3/+0 and has first strike.

{T}, Sacrifice Hidden Garden Entrance: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Monument {W}{U}{B}{R}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Flying, first strike
When Swiftclaw Griffin enters, return a creature you control to its owner's hand.

Vigilance
Conflict Capturer gets +2/+0 as long as a permanent you controlled left the battlefield this turn.

{B}{G}, {T}: Reveal the bottom card of your library and exile it. Target creature gets +X/-X until end of turn, where X is that card's mana value.

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Dawn Over Nizev enters, draw three cards.
When Dawn Over Nizev is defeated, exile it. If you do, you may cast a spell from your hand without paying its mana cost.

Enchant opponent
Cards in enchanted player's graveyard lose all abilities and all names.
If enchanted player would mill one or more cards, they instead mill that many cards plus X, where X is the number of Curses attached to them.

As long as you control an Island, you may cast this spell as a copy of any creature on the battlefield. (This includes casting cost.)

When Sewer Dweller enters or dies, create a 1/1 black Rat creature token with “This creature can't block.”

This spell costs {1} less to cast for each card in your graveyard.
Menace

Flying
When Battlefront Scavenger enters, return target creature card with mana value 3 or less from your graveyard to your hand.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{1}: If you control ten or more nonland permanents, unlock Riddle of Entropy.
As long as the revealed card is a permanent card, each nonland permanent you own is a copy of it.

Flying, lifelink

Draw two cards.

{T}: Add {R}. Put a charge counter on Wistful Automaton.
Remove three charge counters from Wistful Automaton: Transform it.