msem-instigator

When Bird Call enters, search your library for a creature card, reveal it, shuffle, then put that card on top.
{2}, {T}: Target creature gets +1/+1 until end of turn.

Trample
Morph {6} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Equipped creature gets +1/+0 for each Equipment attached to it.
Equip {1}

Target creature you control gets +3/+3 and gains lifelink and trample until end of turn.
Inscribe {3}{G}{W} ({3}{G}{W}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Skysovereign Griffin attacks, it gets +1/+0 until end of turn for each other attacking creature with flying you control.

When Holy War enters, create three 1/1 white Cleric creature tokens.
Creature tokens you control have first strike and lifelink.

Flying, first strike, haste
Whenever Doombringer Dragon attacks, you may sacrifice another creature. If you do, Doombringer Dragon gets +3/+0 until end of turn.

Reveal the top thirteen cards of your library. For each permanent type, you may put a card of that type revealed this way into your hand. Put the rest into your graveyard. (The permanent types are creature, land, artifact, enchantment and planeswalker.)

Create four 3/3 green Elemental creature tokens.
Flashback {7}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Indestructible
If Tarraka-no-Oni would be put into a graveyard from anywhere, reveal Tarraka-no-Oni and shuffle it into its owner's library instead.

When Stoic Observation enters, mill two cards, then you may return a creature card from your graveyard to your hand.
{3}{G}, Exile a creature card from your graveyard: Create a 2/2 green Wolf creature token. You gain 2 life.

As long as Sewer Pack is on the battlefield, you may cast spells named Sewer Pack from your graveyard.
Sewer Pack gets +1/+1 for each other creature on the battlefield named Sewer Pack.

Destroy target artifact, enchantment, or creature with flying.

Whenever you cast a spell from exile, Promised Seeker gets +3/+3 until end of turn.
Prophecy {G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Manifest the top card of your library and the bottom card of your library. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Scry 2.

{T}: Add {C}.
Whenever you tap Masamori Initiate for mana, you may mill a card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}: Look at the top card of your library. You may put the card back or into your graveyard.

{T}: Add one mana of any color.

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

Target creature gets +2/+2 until end of turn. If you cast this spell from exile, that creature gets +4/+4 and gains trample until end of turn instead.
Prophecy {G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Forestheart Elemental enters with a +1/+1 counter on it for each land you control.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}: Mill three cards. Target creature gets +X/+X and gains trample until end of turn, where X is the number of land cards in your graveyard.

When Apprentice Summoner enters, search your library for a creature card with mana value 1 or less, put it onto the battlefield, then shuffle.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)