Body of Effulgent Heliodor _ Overlord

You touch a willing creature and bestow a great boon upon them. For the duration, the target has Resistance to Slashing damage

During the duration of this spell, when the target takes Slashing damage, they can use their Reaction to gain Immunity to one instance of Slashing damage. Once the target uses this Reaction they can not use it again with this casing of the spell.

Using A Higher-Level Spell Slot. The spell's duration can last longer with a spell slot of 7th–Level (up to 30 minutes), 8th–Level (up to 1 hour), or 9th–Level (up to 3 hours).