Crimson red blade

You take a deep breath grasping your weapon . After a second your sword turns bright red. Your weapon gains these benefits for the spell’s duration:

• Your weapon attacks deal extra 1d8 fire damage

• If you attack a fiend or undead they have to make a constitution saving throw against your spell save DC or be unable to regain hit points until the end of your next turn

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the extra damage increases by 1d8 for each slot level above 2nd.