msem-instigator

You may choose not to untap Glacial Shelf during your untap step.
{T}: Add {C}.
{4}, {T}: Tap target creature that's attacking you. It doesn't untap during its controller's untap step for as long as Glacial Shelf remains tapped.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever the second card is put into your graveyard from anywhere each turn, add a quest counter.
1, 2 — You may sacrifice a creature. When you do, you may return target creature card from your graveyard to your hand.
3 — Destroy target nonland permanent an opponent controls.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever another artifact or enchantment you control enters, add a quest counter.
1, 2 — You gain 3 life.
3 — Mill three cards, then return an artifact or enchantment card from your graveyard to the battlefield. Exile Seek the Maker's Egg.
​

Deeplife Cavern enters tapped unless you control a Forest.
{T}: Add {U} or {B}.

Roggar's Gambit deals 2 damage to any target.
Reprise {1}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)
Damage dealt by sources reprising Roggar's Gambit can't be prevented.

Reach
When Archived Intelligence enters, surveil 2. Then if you control a token, draw a card.

Whenever you cast a Pirate spell, create a 1/1 blue and red Pirate creature token with haste.

When Cosmonaut Pioneer enters or leaves the battlefield, choose one—
• Scry 1, then draw a card.
• Create a 3/3 green Alien creature token with trample.
• You gain 5 life.

Scry 2, then draw two cards.

Draw three cards, then discard two cards.

Return target creature, instant, or sorcery card from your graveyard to your hand. Then exile Keep What Was Lost if it wasn't cast from your hand.
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.)

Equipped creature gets +1/+3.
{0}: Until end of turn, Ancestor's Bulwark becomes a 1/3 Spirit artifact creature with flying. Activate this ability only if it isn't attached.
Equip {3}

Whenever you make first contact, Abrasive Citizen gets +3/+0 until end of turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

[+1]: Create a 1/1 red Panda Monk creature token with “{T}: Target player exiles a card from their graveyard.”
[0]: You may sacrifice a creature. If you do, search your library for a creature card and a land card, reveal them, put them into your hand, then shuffle.
[–2]: Xiong Mao deals damage to target creature or planeswalker equal to the greatest power among creatures you control and cards in your graveyard.
[–7]: Any number of players' life totals each become equal to the number of cards in their graveyard.

{2}{R}: Ruthless Mastiff gets +3/+0 until end of turn.

Enchant non-Army creature
When Sinking Pessimism enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature has “{4}: Untap this creature. If it untapped this way, put a stun counter on it.”

Counter target activated or triggered ability.
Metamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Whenever you draw a card, Living Script gets +1/+1 until end of turn.

{1}, {T}: Exile target creature you control until Elsewhere Mirror leaves the battlefield. (It returns to the battlefield under its owner's control.)
{3}: Choose a permanent card exiled with Elsewhere Mirror. Target creature becomes a copy of that card until end of turn.

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.

Untap target artifact or creature. It gains hexproof and indestructible until end of turn.

You may exert Heavenly Bull as it attacks. When you do, it gains indestructible until end of turn. (An exerted creature won't untap during your next untap step.)
{3}{G}{W}: Destroy all nonland permanents with mana value 3 or less. Activate only if Heavenly Bull is attacking and only once.

Flash
Enchant creature
Whenever enchanted creature becomes the target of an ability or spell you don't control or leaves the battlefield, enchanted creature deals 3 damage to any target.

Whenever IG-2 Disassembler enters or attacks, you may sacrifice an artifact. When you do, IG-2 Disassembler deals 2 damage to target player or planeswalker.

Create a 1/1 colorless Construct artifact creature token. If you control six or more artifacts, create a 6/6 colorless Golem artifact creature token instead.
Draw a card.