Each of the people who were able to escape from the basement died a tragic death.
This was the reason why everyone believed Lily because they saw the strange death of those villagers.
And what was more common was that each of them willingly came to the Cursed Graveyard by themselves in the middle of the night and hung themselves on the trees of a small forest.
Now for the part where it was said that the Ouija board was played.
It was indeed played but it was played by Lily all by herself.
She broke all the rules by herself.
Her only motive was to turn this place into a cursed place.
Which she did.
More spirits and ghosts started appearing in the cemetery and slowly this place became a haunted place.
Some stayed here willingly while some were trapped.
Lily used her Black Magic to control this place.