Mike works as a drama provider even without being Gillian's boyfriend, he might be fucking Lena and he fucked Ivy, so put them both in the public and you are done. Of course, the Gillian angle would work better, even if it has been too foreshadowed at this point to hit like a surprise. It's been discussed here for ages, it reminds me of Jon Snow's parentage.I imagine we'd get a fight against Mike and then Jeremy in the final. Or the other way around, but probably not given Mike states he didn't really train fighting so he's unlikely to make it that far, and due to how his fight would be good opportunity to reveal Gillian as his girlfriend who comes to cheer him on, provided she is his gf)
That's what I assumed, chapter 13 will be released in several parts (besides the alpha/beta/final thing), so Billy probably won't be in the first part but probably somewhere later.It's possible, but i think EK might try to have few next chapters cover less ground-time wise, so they can be released faster. IIRC there's a mention in the latest status update that next chapter would be alfa-ready shortly the epilogue to Ch.12? That's not very plausible if there was large amount of story and sex scenes in it.
edit: this part
Next update after the CH.12 epilogue would have to be Ch.13 alpha. Well, i guess it may be a part of Ch.13 instead of the whole thing, so maybe Billy's action would be then another bit of Ch.13 released afterwards. Suppose we'll see.