One in the Chamber: Reloaded

Based on the classic Call of Duty mode with the same name.
You only have one bullet, but you get a bullet back with a kill.

If you have no bullet, attack someone with a Quick Melee to get another one.
(Quick Melee is not available if you have a bullet)

By default, you respawn as a random hero and need 20 kills to win.
Some heroes have abilities and ultimates; you can disable them with Workshop Settings.

ALL CURRENTLY PLAYABLE HEROES:

Doomfist -

• Has no abililities, but his shotgun-like primary is powerful alone.

Junker Queen -

• Can use Commanding Shout for mobility.
• Can use Carnage.

Roadhog -

• Has no abililities, but his shotgun-like primary is powerful alone.

Winston -

• Can use Barrier Projector for defense.
• Can use Jump Pack for mobility, or as a way to kill.

Wrecking Ball -

• Can Roll for mobility.

Ashe -

• Can use her Ultimate Ability after getting the necessary amount of kills.

Cassidy -

• Can use his Ultimate Ability after getting the necessary amount of kills.

Echo -

• Can use Flight for mobility.

Genji -

• Can use Deflect for defense.
• Wall Climb and Double Jump passives work as usual.

Junkrat -

• Can place a Steel Trap that will restock his bullet if someone is killed by it.
• Passive Total Mayhem works as usual.

Mei -

• Only secondary fire is enabled.
• Can use Ice Wall to defend herself.
• Can use Cryo-Freeze to defend herself or restock her bullet.

Sojourn -

• Can use Power Slide for mobility.
• Can use alt fire.
• Can use her Ultimate after getting the necessary amount of kills.

Soldier: 76 -

• Can use Sprint for mobility.

Symmetra -

• Only secondary fire is enabled.
• Can use Teleporter for mobility.
• Can use her Ultimate after getting the necessary amount of kills.

Torbjörn -

• Can use Overload to restock his bullet and get a massive speed boost.

Widowmaker -

• Can use Grappling Hook for mobility.
• Can use her Ultimate Ability after getting the necessary amount of kills.

Ana -

• Can use Sleep Dart essentially as a second bullet on cooldown.

Baptiste -

• Exo Boots passive works as usual.

Illari -

• Can use Healing Pylon as a makeshift shield.

Kiriko -

• Can use Protection Suzu to defend herself.
• Can use her Ultimate after getting the necessary amount of kills.
• Wall Climb passive works as usual.

Lifeweaver -

• Can use Rejuvenating Dash and Petal Platform for mobility.
• Can use his Ultimate after getting the necessary amount of kills.

Lúcio -

• Can use Amp it Up for increased mobility.
• Wall Ride passive works as usual.

Mercy -

• Can use her Ultimate after getting the necessary amount of kills.
• Angelic Descent works as usual.

Zenyatta -

• Can use Orb of Discord to track enemies.
• Can use his Ultimate after the necessary amount of kills, it restocks his bullet as well.

You will only get Ult charge for kills via your primary/secondary fire on the heroes with Ults

If a hero is not listed here, then they are not playable currently.
If a hero used to be listed here, and now is not, then they had to be removed due to bugs (typically involving the "Set Ammo/Max Ammo" actions.)

This is the first code I've posted, so any feedback is appreciated.