>>6716570My theory regarding 1-10 is that they, like she, exhibited special strengths, but, also like she, failed to live up to Brenner's expectations (not hurting the cat, etc), so he had them killed. That's the best explanation I can give as to why Eleven freaks the fuck out as hard as she does when they're taking her to the holding cell, and why she straight up kills them both. We already know she would only go that hard to protect her life or the life of a loved one.
As for interacting with the monster in Limbo, I think that just reinforces the metaphor. She is in the normal world with access to other planes (as opposed to, say, other "realms); likewise, the monster is in the Upside Down with access to other planes. Or, maybe, she just stumbled across some really powerful energy emanating from the monster, in the form of its Limbo persona.
