Lots of interesting ideas here. I’m not going to step in and give you the what’s what on all of this. Mayong and his history, intentions, and indeed his entire persona are meant to remain mysterious. Prophecy of Ro is designed around this vampire becoming a part of the pantheon, but it’s not about him per se.
In fact, there’s a bunch of lore on eqplayers on the Plane of Magic and soon (maybe today or tomorrow), you’ll see an explanation of the Plane of Rage and the origins of Sullon Zek and how she ascended (I loved writing that up, even if she isn’t Vah Shir). We hope to post more before launch and then I’ll have a storyline entry for launch day. The story line piece will give you a few cues as to some folks you might want to talk to when the game launches too.
I will tell you that the shiliskin are not related to the kedge. And yes, Brell was the first to Norrath who created the pact amongst Tunare, Rallos Zek, and Prexus. I’ll let you in on something — the shiliskin already existed in the underfoot (underground of Norrath) when Brell Serilis first arrived. It was the shiliskin and several of the other creatures in Darkhollow that Brell encountered that caused him to create his realm and children elsewhere. Do we know who created the shiliskin? No. Do we know who created Mayong? No. This type of mystery will apply to several other intelligent creatures as well.