Well, this theory is almost identical to my own so I support it.

I put OOX in the Child Timeline after AoL. It makes sense, as Twinrova wasn't killed in the Child Timeline so that would explain how they appear. This evidence alone shows that OOX must be in the Child Timeline, unless you think their death in the Adult Timeline isn't canon for some reason, or you think that Twinrova in OOX is just a cameo. I doubt that they would have been revived between games because I believe that there would be some mention of this.

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