I don't know much about the lore in the life series but my theory is that Etho is behind all of it.
He is an ancient creature that has existed as long as the game (he has play since the first version) and when he realized he is wash up, he somehow makes Grian create this death games so he can show he isn't wash, but he fails miserably every time.
So the watchers and all that are Ethos creation. He knows about everything but plays dum so he isn't found out. That's why he tells pearl "You are a watcher, not a player" (or something like that)
And that's why he is also part of the secret society, cause he knows everything, so it wouldn't be secret if he isn't part of it.
And on limited life, he goes back to Grian with the sword thing because he kinds of feel guilty for making Grian responsible of all of it.
Now som Gemtho thoughts:
Etho falls for Gem on hermitcraft, so he trys to pull her in the death games to have more excuses to interact with her. First it doesn't work well and she ends up possessing his "ex wife". But on secret life he manage to do it.
Also he jas the excuse to "practice" with her on hermitcraft.
That's why Gem is also part of the secret society, he doesn't want to kill her.
And i can talk about this all day but i have things to do 😔
