msem-instigator

As an additional cost to cast this spell, torment yourself. (You lose 3 life unless you discard a card or sacrifice a nonland permanent.)
Destroy target creature.

Whenever you activate an ability of a card in your graveyard or cast a spell from your graveyard, create a 1/1 blue and black Bird creature token with flying and ward {1}.
Whenever three or more creatures you control deal combat damage to a player, return target creature card with mana value less than or equal to that number of creatures from your graveyard to the battlefield.

Swarming Midden enters tapped unless you control a basic Swamp.
{T}: Add {B}.
{1}{B}{B}: Swarming Midden becomes a 2/3 black Rat creature with menace until end of turn. It's still a land. Whenever it attacks this turn, create a 1/1 black Rat creature token with “This creature can't block.”

Flying, haste
When Tech Chaser enters, exile the top three cards of target opponent's library.
Whenever Tech Chaser deals combat damage to an opponent, you may cast a card exiled with it, and you may spend mana as though it were mana of any color to cast it.

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Tegan, the Sparrowhawk attacks, you may pay {R/W}. When you do, Tegan deals 1 damage to target creature if it's tapped. Otherwise, tap it.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Create a tapped colorless Mountain Forest land token. (It has “{T}: Add {R} or {G}.”)

Exile target creature an opponent controls. Each player may search their library for a basic land card and put that card onto the battlefield tapped. Then each player who searched their library this way shuffles.

Flying
You pay {0} to cast your first spell each turn rather than its mana cost. If you cast a spell with {X} in its mana cost this way, X is 8.

Foreshadow {13}. This costs {1} less for each nonland card in your graveyard. (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)
Flying, menace, trample
When The Wickerscreech of Gatstaf dies, destroy target nonland permanent an opponent controls.

Each creature you control enters with an additional +1/+1 counter on it.
Each planeswalker you control enters with an additional loyalty counter on it.

Vigilance, menace, trample, haste
Whenever you cast a spell, you may have Thunderous Avarice consume. If you do, put a +1/+1 counter on it. (To consume, sacrifice another creature or exile a creature card from your graveyard.)
Whenever an opponent casts a spell, they may have Thunderous Avarice consume. If they don't, put a +1/+1 counter on it.

As Timber Range enters, you may pay 2 life. If you don't, Timber Range enters tapped.
{T}, Sacrifice Timber Range: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

{T}: Add {C}.
{4}, {T}, Sacrifice Timeworn Crags: Destroy target nonbasic land. This ability costs {1} less to activate for each nonbasic land you don't control.

You may exile a land card from your hand rather than pay this spell's mana cost.

Once each turn, when you search your library, you may add {B}{B}.

Mountains you control have “{T}: Add {R}{R}.”
[+2]: Exile the top card of your library. You may play that card until the end of your next turn.
[–2]: Conjure six cards named Scorch. Shuffle them and your hand into your library, then draw two cards.

Flying, haste
Whenever another creature dies, Twinfire Dragon gets +1/+0 until end of turn.

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{5}, {T}, Discard a card: Create a 0/0 colorless Construct artifact creature token with “This creature gets +1/+1 for each artifact you control.” It can't block this turn.

{T}: Add one mana of any color.
{T}, Sacrifice Unicorn of the Vale: Add three mana of any one color.

Discard a card: Unseen Maniac gets +1/+1 and can't be blocked this turn.
Whenever Unseen Maniac deals combat damage to a player, draw a card.

Return target creature card from your graveyard to the battlefield with an additional -1/-1 counter on it.

Choose one —
• Unwrite deals 3 damage to target attacking or blocking creature.
• Destroy target artifact.
• Destroy target enchantment.

Flying
Ward—Pay 3 life.
Landfall — Whenever a land you control enters, Valakut Hellkite deals 3 damage to any target.

Whenever you cast a spell that targets, put a loyalty counter on Valeri Kripac and create a 1/1 white Soldier creature token.
[+1]: Add {R}. If you spend this mana on a spell that targets, that spell can't be countered.
[–2]: Exile target instant or sorcery card from your graveyard. You may play it until the end of your next turn. If you do, exile that spell instead of putting it anywhere else.

Search your library for up to three creature cards with mana value 2 or less, put them onto the battlefield, then shuffle.