Blinking Strike

Whenever a creature within 60 feet of you proceeds to cast a spell, you teleport to a space within 5 feet of that creature then make a melee spell attack against it. On a hit, the target takes 2d10 Psychic damage and if it is casting a spell of 2nd level or lower, its spell fails and has no effect. If it is casting a spell of 3rd level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used, and the damage the target takes increases by 1d10.