Desperate Gambit

Choose a source you control and flip a coin. If you win the flip, the next time that source would deal damage this turn, it deals double that damage instead. If you lose the flip, the next time it would deal damage this turn, prevent that damage.

Benalish Knight

Flash (You may cast this spell any time you could cast an instant.)
First strike (This creature deals combat damage before creatures without first strike.)

Debt of Loyalty

Regenerate target creature. You gain control of that creature if it regenerates this way.

Psychic Vortex

Cumulative upkeep—Draw a card. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of your end step, sacrifice a land and discard your hand.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Serra's Blessing

Creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Dwarven Thaumaturgist

{T}: Switch target creature's power and toughness until end of turn.

Abeyance

Until end of turn, target player can't cast instant or sorcery spells, and that player can't activate abilities that aren't mana abilities.
Draw a card.

Island

Plains

Goblin Bomb

At the beginning of your upkeep, you may flip a coin. If you win the flip, put a fuse counter on Goblin Bomb. If you lose the flip, remove a fuse counter from Goblin Bomb.
Remove five fuse counters from Goblin Bomb and sacrifice it: It deals 20 damage to target player or planeswalker.

Mana Web

Whenever a land an opponent controls is tapped for mana, tap all lands that player controls that could produce any type of mana that land could produce.

Mistmoon Griffin

Flying
When Mistmoon Griffin dies, exile Mistmoon Griffin, then return the top creature card of your graveyard to the battlefield.

Heart of Bogardan

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When a player doesn't pay Heart of Bogardan's cumulative upkeep, Heart of Bogardan deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls, where X is twice the number of age counters on Heart of Bogardan minus 2.

Mountain

Roc Hatchling

Roc Hatchling enters the battlefield with four shell counters on it.
At the beginning of your upkeep, remove a shell counter from Roc Hatchling.
As long as Roc Hatchling has no shell counters on it, it gets +3/+2 and has flying.