Arcane Redirection

When you or a target within 80 feet of you take damage from any physical source, you can use your reaction to quickly create a portal in front of the creature receiving the damage, directing the outlet of the damage to another creature you can see within 80 feet of you, except for the attacker. you must make a DC 14 Dexterity (Sleight of hand) check to create the portals in time. If you are diverting a melee attack, the attacker can make a dexterity save at disadvantage to your spell save DC.

if you fail the initial Dexterity check, the spell fails.