Eldritch Inferno

You ignite a creature within range with a burst of fiery energy. The target must make a dexterity saving throw or take 3d6 fire damage on a fail or no damage on a success. Alternatively, you can designate one weapon within range and it becomes enchanted with flames. Whenever a weapon attack is made with the designated weapon, apply an additional 2d6 fire damage on a hit, or half as much on a miss. If used to enchant a weapon temporarily, the enchantment lasts up to 3 rounds or when an attack is made, whichever happens first and if you use this spell again then the enchantment ends. You can only have one weapon enchanted in this way at a time.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.