Having randomized heroes is a good idea.

Having purely randomized heroes, with no rules on team composition can get to feel like whichever team has the best RNG automatically wins. Killing the fun of this gamemode.

But there are some easy rule fixes on next-spawns:

If a team has 3x healers, don’t spawn more healers.

If a team has 0x healers, next spawn is 100% a healer.

If the team has 2x self-heal non-healer, don’t spawn any more. (These are overpowered in this mode).

If one team has a Pharah, and the above conditions are met, spawn a Soldier/McCree/Sombra/Hanzo. (If they don’t already have one).

Don’t spawn 3x of the same hero.

Maintain ultimate charge on death.

Resurrect gives you a different hero.

(Jovial_Bard on Reddit)

(Jovial_Bard on Reddit) Both teams get different heroes between rounds on KOTH (Jovial_Bard on Reddit)

Limit respawning as the same hero repeatedly. (BrownCoat40 on the forums)

There, fixed!

Pixel had a really interesting idea,

How to fix Mystery Heroes

Mystery Heroes, but you get 3 characters to choose from on death.

I’d go further, and say make those 3 heroes, 1 random DPS, 1 random Healer, 1 random Tank.

He called his “Mystery Draft”, but “Mystery Hero Select” would also work.

Also, as little have mentioned below, maintain ultimate charge between deaths, so that one team doesn’t snowball as hard towards a landslide win.