As a reaction, which you use when you are hit by an attack you can see or when you take fire damage, you can create a rushing torrent of water as a shield. You have resistance to bludgeoning, piercing, and slashing damage from nonmagical weapon attacks until the start of your next turn, including against the triggering attack.
Additionally, you have resistance to fire damage and advantage on saving throws against the burning condition until the start of your next turn.
You can expend 1 additional mana or psi to trigger the spell when a creature that you can see within 18 meters is attacked or takes fire damage. The attacked creature gains the benefits instead.