With a trickle of ones blood the flesh on this abyssal weapon shift into a bloodshot eye. Due to its method of charging, this magical martial ranged weapon does not have the loading property.   

Feed the Abyss: Over the course of a short rest, you can charge the Abyssal Flintlock by dripping your own blood down its barrel and spending a hit dice. For each hit die spent in this way, you roll the hit die and the weapon gains a number of charges equal to the total of the rolled hit dice. The weapon can absorb no more than 3 hit dice of blood per short rest. 

Shot Selection: When you take the Attack action, you can spend charges in the following ways to make a ranged weapon attack using this weapon, otherwise you spend 1 charge to make a normal attack with it.

Abyssal Shard (1 charge): On a hit, the weapon deals its normal piercing damage.
Psychic Shot (2 charges): On a hit, the weapon deals its normal piercing damage plus 1d6 of psychic damage.
Septic Shock (2 charges): On a hit, the weapon deals its normal piercing damage and the target must succeed on a DC 15 Constitution saving throw or become poisoned until the end of your next turn.

Proficiency with a Pistol allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Ignore Weapon Property: Loading, Bonus: Magic, Weapon Property: Light, Damage: Psychic, telepathic creature, Loading, Range, Ammunition (Firearms), Vex