Transmute Lifeblood

You alter your lifeblood, suffusing it with primordial energy. When you cast the spell, choose one of the following options, the effects of which last for the duration of the spell. While the spell lasts, you can end one option as a bonus action to gain the benefits of a different one.

When you take piercing, slashing, force, or necrotic damage, you can choose a creature within 5 feet of you, causing the blood you spill to spontaneously react with the air with your current element. 

Scorch. The target must succeed on a Dexterity saving throw or take 3d6 fire damage and be covered in liquid fire, causing their next attack to have disadvantage on their next attack roll until the end of their next turn.

Frost. The target must succeed on a Dexterity saving throw or take 3d6 cold damage and be partially flash frozen, reducing their movement speed by 15 feet until the end of their next turn.

Corrosive. The target must succeed on a Dexterity saving throw or take 3d6 acid damage causing acid blood to splash on them. The creature then rolls a 1d20. On an odd roll, the creatures natural armor is reduced by 1, or the armor class its armor provides is reduced by 1, but only if it is nonmagical. If this causes an armor to provide no AC bonus, then it is considered destroyed and beyond typical repair. If a creatures AC is from a spell or magical ability, or based on their dexterity, then it is not lowered.

Shock. The target must succeed on a Dexterity saving throw or take 3d6 lightning damage and making them unable to use their reaction due to the electroshock.

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 the 3rd.