(There's currently a problem with the anti-cheese of hiding in hider's spawn, I know a fix for it, but it is currently not working correctly. Once I'm active again I'll look into it.)
I remade my old Hide-and-Seek workshop with my better knowledge of how Workshop works.
Play this Workshop in the Control Gamemode only. I recommend having Busan and one of the two Lijang Tower maps disabled.
By default, the hiders (Team 2) are granted 2 minutes to hide, and the seeker (Team 1) is given 15 minutes to find all the hiders.
The Seekers are granted a win when no living players are alive on the Hiders team, and the Hiders are granted a win when the time runs out, or the seeker leaves.
There is a ring with sparkles on every point, stand in the ring for 5 seconds to be teleported to the next point map. (This refers to that all control games have 3 separate points. They are all loaded at once in the Control Gamemode, which allows players to create ways of going through them all in a single round.)
The seeker gets notified when some one teleports with a simple small "!" on their screen.
The workshop rules modifies Player Health, Speed, and Damage, so changing these in Hero settings will just get them reverted. All other "Hero" options in the Custom Game Settings are untouched so you are free to enable/disable anything you want. (Heros, abilities, weapons, etc.)
Ultimates are disabled for all players. I'll update the game later to make this easily optional.
The hiders are unable to deal damage, but by default, all abilities are enabled.
I implimented an anti-Sombra invisible cheese though in one of the workshop rules. That wouldn't be fun to seek against, right? I did this so you don't have to.
Once the seeker is let out, any hiders that attempt to hide in the spawn will instantly be killed to avoid unfun cheese. The seeker is free to die or sit in their own spawn as they please, since it doesn't affect anything.
If the seeker leaves mid-game, and there's no one to replace them, the game ends after 20 seconds, giving the victory to the hiders.
It is possible to add more than one seeker, there should be no issue with it.
There is a fix to avoid being teleported into death in the Ilios Well map. There is currently no implimentation to fix being inside walls when being teleported on specific points on specific maps, but if anyone is hiding in them, the seeker can easily get teleported right on top of them. I don't see this as a pending issue.
The control point is disabled for the entire game, so you don't have to worry about players capturing it.
If the workshop code ever breaks, you can paste the code snippet with no problem into workshop. Everything is built from the workshop alone. All you need to do is set it to the Control Gamemode only after pasting, and set the Seeker's team (Team 1) size to 1 or to what you wish.