Reverse Magic
Tier 1 Epic abjuration
Casting Time: 1 reaction, which you take when you see a creature within 300 feet of you casting a spell
Range: 300 feet
Components: S
Duration: Instantaneous
You interrupt a creature casting a spell with a blast of antimagic. If the creature is casting a tier 1 Epic spell or non-Epic spell, that spell fails and has no effect. If the creature is casting a tier 2 Epic spell or higher, you must attempt an ability check using your spellcasting ability (DC 24 for a tier 2 Epic spell and DC 28 for a tier 3 Epic spell). On a success, the creature’s spell fails and has no effect. At your discretion, spells which are successfully reversed explode spectacularly, dealing 10d6 arcane damage to the casting creature.
At Higher Levels. When you cast this spell as a tier 2 Epic spell or higher, the interrupted spell has no effect if its tier is less than or equal to the tier used to cast this spell. Additionally, the damage caused by a reversed spell increases by 5d6 per tier above tier 1.
Ref: ELCR p102