Wanna try something new? Well we have some gamemodes

i know i havent posted in a while but whatever im sorry. well if you wanted to know how to create the boss fight game mode here it is
Heroes: Pick a hero you want the boss to be and exclude all other heros so they can only choose that hero
Make the hero you chose have alot of hp alot of damage and a bit of damage resistance
Settings:
Set it to elimination for the feel of having only one life
maybe change some of the cooldowns abit on the attacking

this is a 6v1 5v1 4v1 or 3v1
any lower than that it its just really hard

Keep in mind the settings for the boss may not be ideal you might have to change them to your liking for example. maybe roadhogs hook is to powerful put it on a longer cooldown or get rid of it entirely
if the boss has to much hp. Lower his damage resist or lower his hp
If the boss does to much damage then lower his damage
You can disable or enable health packs
but if you do then make it so the boss receives less healing