msem-instigator

Equipped creature gets +1/+1 and has vigilance and lifelink.
Equip {3}

First strike, haste
Whenever Kragnoss' Battlecharger attacks, it gets +1/+0 until end of turn for each attacking creature.

{T}: Add {C}.
{T}, Tap an untapped artifact, creature, or land you control: Add one mana of any color.
{T}: Choose a card name, then reveal the top card of your library. If that card has the chosen name, you may sacrifice Sealed Archives and draw a card.

When Mystic Seer enters, each player may scry 1.
{2}{U}: Draw a card, then discard a card.

As Mercantile Accords enters, choose a number.
Whenever an opponent casts a spell with the chosen mana value, you draw a card and create a Treasure token.

Flying
Whenever you cast a creature spell, creatures you control get +1/+1 until end of turn.
Whenever you cast a noncreature spell, create a 2/2 red and white Cat Knight creature token.

{1}{R}{W}: Create a 2/1 red and white Fox creature token. It gains haste. Sacrifice it at the beginning of the next end step.
Whenever Fox of a Brisk Autumn attacks, attacking Foxes you control get +1/+1 until end of turn.

Look at the top four cards of your library. You may reveal a permanent card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Rethia Cultivator enters, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

Redgill Corsair gets +1/+0 as long as you control an artifact.
When Redgill Corsair dies, create a Treasure token.

Trample
{2}{G}{G}: Put Canal Lurker from its owner's graveyard on top of its owner's library.

You have no maximum hand size.
{T}: Add {C}.
{3}, {T}: Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

You may cast What Remains of Samuel Quinn from your graveyard and from the battlefield. It costs {G}{G} more to cast this way.
What Remains of Samuel Quinn enters with your choice of X counters from among +1/+1, vigilance, reach, and trample.

You may exert Migrating Herd as it attacks. When you do, sacrifice a land and draw a card. (An exerted creature won't untap during your next untap step.)

Riv's Safehouse enters tapped.
When Riv's Safehouse enters, you may mill two cards.
{T}: Add {U} or {B}.

Creatures your opponents control get -3/-0 until end of turn.
Draw a card.

Destroy target creature. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Target creature gets +2/+2 until end of turn. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

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.)
{5}: Unlock Key to the Nexus. If {W}{U}{B}{R}{G} was spent to activate this ability, you may cast the revealed card without paying its mana cost. Otherwise, put that card on top of your library.

{T}: Add one mana of any color. When this mana is spent to cast an enchantment spell with mana value 5 or greater, draw a card.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Curious Cubs has first strike as long as its attacking.
When Curious Cubs has three or more +1/+1 counters on it, remove them all and transform it.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Reach
Wanderlust — Voliv Skyhunter gets +2/+0 and has first strike as long as you control four or more differently named lands.

Flying
Whenever Starborne Hellkite attacks, choose two—
• Starborne Hellkite deals 4 damage to any target.
• Destroy target artifact or land.
• Creatures you control get +2/+0 until end of turn.

Trample
Ride {3}{G} ({3}{G}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)