Gaze of the Veil, Tanegashima of the Ashen Veil

Known as Gaze of the Veil, this ancient tanegashima is no mere weapon, but an instrument through which the Ashen Veil observes the world. Its pale wood gleams like bone under moonlight, and the silver sap veins glow with a steady, watchful radiance. When drawn, the rifle demands absolute stillness, breath held, heartbeat measured, until the moment of release feels less like an action and more like a judgment rendered. 

Those struck by its fire speak of a terrifying clarity in their final seconds, as though they were seen completely, laid bare beneath an unseen gaze. Some claim the Veil itself peers through the sights, choosing not where the shot lands, but when the world must change.

You have a +3 bonus to attack and damage rolls made with this magic weapon.

Your normal and long range with this weapon are tripled (to 300/1200), and while wielding it, you have advantage on Wisdom (Perception) checks.

When you take the Attack action to make an attack with this sniper rifle, you can choose to steady yourself. Your next attack has its critical hit range increased by 1. You can use this feature only if you haven't moved during this turn, and after you use it, your Speed is 0 until the end of the current turn. 

You can choose to attune to this weapon. While attuned, you gain the following benefit:
Elemental Armament.
The rifle deals an additional 2d8 damage of a type of your choice: acid, cold, fire, force, lightning, necrotic, poison, psychic, radiant, or thunder. You may choose the damage type each time you complete a long rest

As a bonus action, you can prematurely change the rifle's elemental damage type to another option from the list above.

Breakthrough.
When you score a critical hit with this weapon, elemental force tears through the target’s defenses. Fractures of power linger, reducing the creature’s Armor Class by 1d4 + 2 until the end of your next turn.

Piercing the Veil
When you score a critical hit with this weapon, you expose the target to perfectly timed follow-up strikes. Creature of your choice within 30 feet of you can use their reaction to make one attack with advantage against the target of the critical hit.

An instrument of ranged precision, the Sniper Rifle can take shots from distant, nearly invisible ranges.

Notes: Bonus: Magic, Damage: Acid, Advantage: Perception, Damage, Combat, Ammunition, Heavy, Loading, Two-Handed, Firearm, Sighted