Magnetic Mountain

Blue creatures don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player may choose any number of tapped blue creatures they control and pay {4} for each creature chosen this way. If the player does, untap those creatures.

Mountain

Scald

Whenever a player taps an Island for mana, Scald deals 1 damage to that player.

This spell can't be countered.
Fry deals 5 damage to target creature or planeswalker that's white or blue.

Spinal Villain

Chaotic Backlash

Chaotic Backlash deals damage to target player equal to twice the number of white and/or blue permanents they control.

Curse of Marit Lage

When Curse of Marit Lage enters, tap all Islands.
Islands don't untap during their controllers' untap steps.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Parch

Choose one —
• Parch deals 2 damage to any target.
• Parch deals 4 damage to target blue creature.

Burnout

Counter target instant spell if it's blue.
Draw a card at the beginning of the next turn's upkeep.