STR and CON increase by 1, CHA decreases by 1.

You have Darkvision out to 120 feet but your sensitive eyes make you vulnerable to Radiant damage.

You do not experience the intended effects from drinking potions and instead must roll on the table below to determine the outcome. You can still be healed by magical healing from spells.

1 - You find the potion extremely disagreeable and lose 2d20 health.
2 - The potion makes you queasy and your CON is reduced to 12 until you long rest. 
3 - The potion makes you gassy, and you cast Gaseous Form on yourself. 
4 - The potion makes you lightheaded, giving you +2 to your CHA score and -2 to your WIS score until you long rest. 
5 - The potion makes your head fog up, giving you disadvantage on INT checks and saving throws and resistance to Psychic damage until you long rest.
6 - You find the flavor delightful and gain an inspiration die if you do not already posses one.

Demons are born of other planes and have excellent resilience. You have resistance to Fire, Necrotic, Poison, and nonmagical Bludgeoning, Slashing, and Piercing damage.

Demons have strange neural pathways that make them difficult to penetrate. Your mind cannot be read, and you cannot be put to sleep by magical means.

You are proficient in martial and simple weapons as well as shields. Once per shot rest you can evade the extra damage from a from a critical hit made against you.