Very interesting theory, thank you for sharing it!
I remember i had my own more "Jumanji-like" story, but it was only about the 1st VHS series :
A long time ago, the Gatekeeper was charged with the task of guarding the six harbingers, who have been imprisoned in a cemetery's crypt, up a steep hill. He would ensure they would stay inside, and that nobody would try to enter the cemetery.
But an eternity of being a guard was boring, and the Gatekeeper soon had a devilish idea to entertain the harbingers (but especially himself).
Instead of just scaring unwanted visitors away, he decided to make them play a game, his game. A game from which they would never return.
As the years passed, the rumours were spreading in the surrounding villages. Some people tried to defy the Gatekeeper, but they lost, and were banished forever in the black hole.
Until one day, a group of brave young people (or stupid young people according to what is said) defied him and, after almost an hour of suffering, won. One of them managed to enter the crypt, and resist to his worst nightmare.
Defeated, the Gatekeeper and the harbingers were imprisoned in board game boxes, which were then projected all over the world in a tremendous flash of light.
The group was free, as well as all the other people who once played the game.
The hill and the surrounding villages are now peaceful again, but beware : If one were to find the boxes, open them, and start a new game, they would awaken the Gatekeeper and face his game, and their WORST NIGHTMARE!