As a reaction, which you use when a creature that you can touch or see within 10 meters casts a spell, you can dampen the spell, making it easier to avoid or resist. Roll a d4 and subtract the result from the spell’s attack bonus or spell save DC. You can do so after the roll but before any effects of the roll occur.
You can expend 2 additional mana or psi to roll 2d4.
You can expend 4 additional mana or psi to roll 3d4.
Counterspell. You can expend 1 additional mana or psi to attempt to interrupt the spell instead of dampen it. Make an ability check using your spellcasting ability which you are proficient with. The DC equals the creature’s spell DC + the spell’s effective mana. If you have identified the spell being cast, you have advantage on this ability check.
On a success, the creature’s spell fails and has no effect.
On a failure, you dampen the spell as normal.
A spell’s effective mana is normally the amount of mana it was cast with, including augmentation. If a feature lets a spell be cast without expending mana then the spell’s effective mana is its normal mana cost.
You gain a +1 bonus to your ability check for each additional mana or psi expended.