msem-instigator

{T}: Add {B}.
{B}, {T}: Target creature gains menace until end of turn.

Flash
When Hostile Takeover enters, you may counter target noncreature spell.
At the beginning of your upkeep, you may put a progress counter on a Project you control.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{3}{U}: Target creature gains slipstream until end of turn.

Whenever a nonland permanent enters under an opponent's control this turn, gain control of that permanent until the end of your next turn. It gains haste until end of turn.

When Raikai Seafarer enters, you may search your library for up to three cards named Raikai Seafarer, reveal them, put them into your hand, then shuffle.

First strike
Purpose Elemental gets +1/+0 for each Aura attached to it.

Relonche Spy enters under the control of an opponent of your choice.
Relonche Spy can't block.
During each of Relonche Spy's owner's turns, they may cast a card from your graveyard by paying life equal to its mana value rather than paying its mana cost.

Draw three cards.

Whenever Last Priest of Hadak attacks, you may discard a card. If you do, draw a card.
Whenever you discard a card, you may exile that card from your graveyard. During any turn you dealt damage to a player with a Dragon or Shaman, you may play that card.

When Prismatic Basilisk enters, you may search your library for a permanent card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
{2/W}{2/U}{2/B}{2/R}{2/G}: Prismatic Basilisk gets +5/+5 and gains flying until end of turn.

Enchant creature
Enchanted creature gets +1/+0.
Whenever enchanted creature attacks, target creature can't block this turn.

When Faithless Deserter enters, you may sacrifice a creature. If you do, each opponent sacrifices a creature.

Flash
Flying
You may cast creature spells with flying as though they had flash.
Whenever another creature with flying you control enters, this creature gets +1/+1 until end of turn.

Whenever you cast a spell from exile, put two +1/+1 counters on Midnight Vagrant. It gains menace until end of turn.
{1}{B}{B}: Exile the top card of target opponent's library. You may play that card during any turn you attacked with a Rogue, and you may spend mana as though it were mana of any color to cast it. Activate only as a sorcery.

As Den of Vice enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}, {B}, or {R}.

Activated abilities of creatures you control cost up to {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.
Draw a card.

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

{T}, Sacrifice Ruined Citadel: Search your library for a Mountain or Plains card and put it onto the battlefield tapped, then shuffle.

First strike

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create two 1/1 colorless Construct Actor creature tokens.
II — Creatures you control gain first strike until end of turn.
III — Creatures you control get +1/+0 until end of turn.

Flying, lifelink
Pay 5 life: Put target permanent card in a graveyard onto the battlefield under your control.

Enchant player
Enchanted player may play an additional land on each of their turns.
Enchanted player may play lands from their graveyard.

Counter target spell if four or more mana was spent to cast it.

Once during each of your turns, when you sacrifice a creature, enchantment, or planeswalker, you may choose one —
• Search your library for a card that shares a card type with the sacrificed permanent, reveal it, put it into your hand, then shuffle.
• Target opponent sacrifices a permanent that shares a card type with the sacrificed permanent.