Bloodflame Blade

You engulf a nonmagical weapon you hold with bloodflame, turning it into a magical weapon until the spell ends. For the duration, the weapon deals an extra 1d4 fire damage when it hits. If you stop holding the weapon, the spell ends.
When you score a critical hit with the weapon, it deals anadditional 5d4 piercing damage and the spell ends.
At Higher Levels.
When you cast this spell using a spell slot of 2nd level or higher, the additional piercing damage increases by 1d4 for each slot level above 1st.