If you've played Flanker Duel Mode, this is essentially the same thing but with different enemies.
Select your desired enemies by shooting the Red/Green Buttons.
Toggle Switches for bots:
Mercy: Fire Pistol
Pharah: Use Abilities (Conc Blast and Jump Jet)
Echo: Use Abilities (Focusing Beam and Sticky Bombs) (Flight is always used, as she would be on the ground otherwise)
Press (Interact) to spawn your selected enemies. Press (Crouch) + (Interact) to kill all enemies.
Shoot the Red Button on the right of the Heal Button (on Paris) or underneath the 3rd Arena Teleporter Button (On Dorado) to spawn a friendly bot for you to heal! Look at your teammate and jump to enter Anchor Selection Mode. While in this mode, walk to your desired location and crouch to confirm the Anchor Point. Your friendly bot will now strafe around this area.
Say "Acknowledged" to teleport back to the Enemy Toggle Switches.
The Big Yellow button turns off/on invulnerability.
When invulnerability is turned off, additional switches will appear that allow you to modify the damage dealt by each bot.
Cooldowns/Ammo will be reset after all enemies have been killed. If you'd like to reset your cooldowns early, say "Thanks".
Current Available Maps: Paris, Dorado