: The next time a green source of your choice would deal damage to you this turn, prevent that damage.

: The next time a white source of your choice would deal damage to you this turn, prevent that damage.

Prevent all combat damage that would be dealt this turn.

Prevent the next X damage that would be dealt to any target this turn. Until end of turn, you may pay any time you could cast an instant. If you do, prevent the next 1 damage that would be dealt to that permanent or player this turn.

Enchant enchantment

At the beginning of the upkeep of enchanted enchantment's controller, that player may pay any amount of mana. Power Leak deals 2 damage to that player. Prevent X of that damage, where X is the amount of mana that player paid this way.

Rock Hydra enters with X +1/+1 counters on it.

For each 1 damage that would be dealt to Rock Hydra, if it has a +1/+1 counter on it, remove a +1/+1 counter from it and prevent that 1 damage.

: Prevent the next 1 damage that would be dealt to Rock Hydra this turn.

: Put a +1/+1 counter on Rock Hydra. Activate only during your upkeep.