Mind Spike, Variant (5e Spell)
From D&D Wiki
|Casting time:||1 reaction, which you take when a friendly creature within 10 feet of you is targeted by an attack.|
You attempt to interrupt an attack by psionically piercing through the mind of the attacker.
The target must succeed on an Intelligence saving throw or gain disadvantage on the triggering attack and become vulnerable to psychic damage until the end of your next turn.