Hollow

"The cavity in their head may be an eye, or a bullet hole."
"If it is, it must have been the work of the revolver in their hand."
"That person points the gun at you."

A man in a grey coat stands before a crowd of bandits, carrying a Revolver. The man takes aim at his own head and the revolver's hammer click-clicks away, leaving only the man in the grey coat remaining on that shaded forest path.
You, through some way or another, found a magic revolver. The more you use it, the more you become like the creator of the Revolver.

Le Trou - Level 3

"You don’t fear the pointed gun. Even if they were to pull the trigger…"
"It doesn’t matter how many times the hammer strikes."
"You know the bullet will hit that person’s head."

Ashen Revolver
You gain proficiency in Firearms.
When you take this subclass, you acquire a special revolver. You may summon or dismiss the Revolver at any time.

Ashen Revolver;
Martial Ranged Weapon (Firearm). 1d10 piercing. 40/120 foot range. Considered Magical for the purposes of bypassing resistances and Immunities.

At level 7, the Ashen Revolver gains a +1 to attack and damage rolls.
at level 10, the Ashen Revolver's damage increases to 2d8, and it gains a +2 to attack and damage rolls instead.
At level 15, the Ashen Revolver gains a +3 to attack and damage rolls instead.

Ashen Bullets
Whenever you roll initiative, you load 5 special bullets into the Ashen Revolver. At the start of each of your turns, you load 1 bullet into the revolver if you have less than 5 bullets loaded.
Each attack you make with the Ashen Revolver consumes 1 Ashen Bullet. If you make an attack with the Ashen Revolver while it has no Ashen Bullets loaded, you can still make the attack, but you don't add your ability modifier to the attack roll or damage roll.
Whenever a creature is reduced to 0 hit points while within 50 feet of you, you reload your bullets back to 5.

Gloomy City Rain
You are not impacted by negative effects caused by snow, rain, fog, or stormy conditions. When you take the hide action while in dim light or darkness, or are in weather conditions you ignore the negative effects of, you have advantage on the roll.

Hole in the Man - Level 7

"Misfortune, once it takes aim, is destined to return with a bite."

Smoking Gun
While you have less than 5 Ashen bullets, you can use a bonus action to fire the Revolver at yourself. When you fire the Revolver at yourself, roll a d6. If the result is equal to or less than your loaded Ashen Bullets, the gun fires, automatically hitting a single creature within range. If the result is higher than your loaded Ashen Bullets, the gun strikes an empty chamber, the gun doesn't fire and you load 2 Ashen Bullets, up to 5 loaded bullets.
When making an attack through this feature, you expend 1 Ashen Bullet as normal.
At level 10, you can use Smoking Gun as part of the Attack action, replacing one attack you make as part of that action. You can use Smoking Gun no more than twice on your turn.

Grey Coat
When you hit a creature with the Ashen Revolver after having already hit a different creature with the Ashen Revolver during the same Attack action, the attack deals an additional 1d6 psychic damage, and you regain hit points equal to the psychic damage dealt.
At level 15, the damage increases to 1d8 Psychic damage.

Le Trou de Vidange - Level 10

"Thus man has become null, leaving only the ashen behind"

Black Wings
At the start of each of your turns, you gain 1 stack of 'Black Wings'. You deal 1 additional damage with attacks made by the Ashen Revolver for each stack of Black Wings you have. This damage can trigger up to (Black Wings/4) times per turn. Black Wings has a maximum stack of 12.
Your attacks made with the Ashen Revolver gains an extended crit range, increasing to 19-20 at 4 Black Wings, 18-20 at 8 Black Wings, and 17-20 at 12 Black Wings.
Black Wings expire at the end of combat.

When a creature within 50 feet of you is reduced to 0 hit points, you heal hit points equal to your proficiency bonus, and you gain a +1 to attack and damage rolls until the end of your next turn. This can trigger up to 2 times per turn.

Gunslinger in Nauseating Light
Ranged attacks made against you have disadvantage if you are in Bright Light, or while in weather conditions you ignore the negative effects of.
On a critical hit with the Ashen Revolver, the creature becomes Vulnerable to Piercing damage until the end of your turn. If the creature is resistant to Piercing damage, they lose that resistance until the end of your turn instead. If the creature is immune to piercing damage, they become Resistant to Piercing damage until the end of your turn instead.

L'Hémorragie interne - Level 15

"A single gunshot, Fired into the dark night's reflection on the glimmering sight."
"The bullet… will meet the gaze of another."

Hollowing Chamber
For every 3 Ashen Bullets you expend during a turn, you heal 1d4 hit points and gain a +1 to attack and damage rolls next turn. This can trigger up to 3 times per turn.
Your maximum amount of Ashen Bullets increase to 6. Features that set your Ashen Bullets to 5 set them to 6 instead. Smoking Gun can be used while you have 5 or fewer Ashen Bullets instead of fewer than 5.

Boucher un trou - Level 18

"Gazes beyond reckoning, bullets beyond counting. The lone hammer strikes twenty-four times…"
"And the barrage, restless under the shade, shall fall like torrential rain"

Hairpin Trigger
When you expend at least 4 Ashen Bullets during your attack action, you may use your bonus action to make 2 additional attacks. The two additional attacks deal only the weapon's normal damage and don't benefit from any feature that adds additional damage. Both attacks must target the same creature.

Hollow
Oncoming fortune will slip past if you avoid it. Misfortune you thought to avoid will come back to bite you. Although the gun was pointed at their head, the bullet came your way.

As an action, you may activate this feature. When you activate this feature, you gain 'Eclipse in Black and White', and all allies within 50 feet of you have their Crit Range extended by 1 until the end of their next turn, additionally you gain 2 Black Wings stacks, up to the maximum of 12. Eclipse in Black and White lasts until you use the second activation of this feature.
While you have Eclipse in Black and White, you may activate this feature again using an action. When using this Second activation, target up to 6 different creatures within 50 feet of you.

The chosen creatures must make a Dexterity saving throw. Those who attempt to evade the coming bullet are struck directly, while those who fail to move are merely grazed.
The DC of the Dexterity saving throw equals (4 + your Proficiency bonus + your dexterity Modifier).
On a Success, the creature takes damage equal to 2 rolls of your Ashen Revolver's damage dice. On a Failure, the creature takes half as much damage.

Once you use the Second Activation of this feature, you cannot use this feature again until you reduce a creature to 0 hit points using your Ashen Revolver, or until you finish a long rest.
After using the Second Activation, your next activation triggers the First activation effects.