msem-instigator

Whenever Pelaski Valiant becomes tapped, target creature gets +1/+1 until end of turn.

Double strike

All damage that would be dealt to target creature you control this turn is dealt to another target creature you control instead. Both those creatures get +1/+1 until end of turn.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Return a permanent you control to its owner's hand.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Masha's Lightbound becomes tapped for the first time each turn, untap Masha's Lightbound and each other creature you control.
{W}, {T}: Exile target card from a graveyard.

Players can't cast spells with mana value greater than the number of dissent counters on Kazimir's Ban.
{2}: Put a dissent counter on Kazimir's Ban. Any player may activate this ability.

{1}{W}, {T}: Other creatures you control get +1/+1 until end of turn.

Vigilance
Creature spells you cast cost {2} less to cast.
Other creatures you control can't attack or block.

Vigilance
Players can't untap more than two lands during their untap steps.

When Establish Guard enters or leaves the battlefield, create a 1/1 white Human Soldier creature token and you gain 1 life.

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.)
Tap four untapped creatures you control: Unlock Clockwork Astrolarium. If the revealed card is white, put it into your hand. Otherwise, put it on top of your library.

When Blossom-Ash Trance enters, you gain 3 life.
At the beginning of each end step, if you gained 3 or more life this turn, draw a card.

Whenever Barricade Watch is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

This spell costs {2} less to cast if a creature died under your control this turn.
Flying

Enchant creature
When Aura of Leadership enters, create four 1/1 white Human Soldier creature tokens.
Enchanted creature gets +2/+2.

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.)
{0}: Unlock Tesseract Conjecture. If the revealed card shares a mana value with three or more permanents you control, cast it without paying its mana cost.

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.

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.)
When the fourth spell of a turn is cast, you may unlock Mirror Cipher. If the revealed card is an instant or sorcery card, cast it without paying its mana cost and copy it. You may choose new targets for the copy.

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}, Sacrifice two Clues: Unlock Hall of Lost Histories and put the revealed card into 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}, Discard two cards: Unlock Cryptic Fragment. If the revealed card is a basic land card, put it into your hand.

Each creature you control that's enchanted or is an enchantment gets +1/+1.
{2}{W}{W}: You may reveal an enchantment card you own from outside the game and put it into your hand.

Uncharted Haven enters tapped.
As Uncharted Haven enters, choose a color.
{T}: Add one mana of the chosen color.

Treacherous Den enters tapped.
{T}: Add {B} or {R}.
{2}{B}{R}, {T}, Sacrifice Treacherous Den: Draw a card.

Stunning Cascade enters tapped.
{T}: Add {U} or {R}.
{2}{U}{R}, {T}, Sacrifice Stunning Cascade: Draw a card.

Sheltered Haven enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}, {T}, Sacrifice Sheltered Haven: Draw a card.