So Tiny

Flash
Enchant creature
Enchanted creature gets -2/-0. It gets -6/-0 instead as long as its controller has seven or more cards in their graveyard.

Gargoyle Castle

{T}: Add {C}.
{5}, {T}, Sacrifice Gargoyle Castle: Create a 3/4 colorless Gargoyle artifact creature token with flying.

Quench

Counter target spell unless its controller pays {2}.

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Spell Snuff

Counter target spell.
Fateful hour — If you have 5 or less life, draw a card.

Rewind

Counter target spell. Untap up to four lands.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Island

Negate

Rain of Revelation

Exclude

Counter target creature spell.
Draw a card.

Enthralling Hold

Enchant creature
You can't choose an untapped creature as this spell's target as you cast it.
You control enchanted creature.

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It has every creature type.)

Turn into a Pumpkin

Return target nonland permanent to its owner's hand. Draw a card.
Adamant — If at least three blue mana was spent to cast this spell, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Mesmeric Glare

Counter target spell with mana value 3 or less. (Then exile this card. You may cast the creature later from exile.)