This is an idea for a collab story-writing event as soon as Karikamiya's writing contest for July is over so I don't steal any of her thunder. So, between the July and the August contests, I think.
The idea is this - the worlds are at war. Mephosauria, having discovered the existence of other dimensions during the events of First Crisis, has built gateways to the worlds of Diakatan and Tir na Nog so he can "research" them at the expense of quite a few lives.
Those who want to participate can add their own worlds. For example, ManraptorHurrr can add his place where The Raven and two other unfinished stories were set (I can't remember their names) or Shisaac can add his Monstrous War universe. By the way, Shisaac, sorry about adding Mephosauria without asking first. I could change it to somebody from Tir na Nog or Incendarment if you want.
Those who want participate can contact me here. The contest begins after the Insanity competition is over.