Mmhmm, I've only managed to engage one of my characters thoroughly, Fury.
I suppose if I included every tenuous link
Fury; currently riding high on a Angar Ryllan flagship with a fancy new toy, defeated by Skallagrim, fought General Freedom (not sure how this is canonized, the first battle which took place with Sukoh caught in the background ended with Freedom being captured.) Had a minor skirmish with Sukoh and some other characters before leaving. Fought Kanitah and beat him up a bit before leaving, eventually re-encountered Kanitah and killed him, taking his world machine, which brings us to the present day with Fury.
Clockwork Man; Won the Nexus of Worlds tournament and recieved the Dreamer's ability to transport through space (which is actually pretty important, as it leaves him as one of the few ways to access the Nexus, which could make him a valuable target if people knew.) Dissapeared for a bit and probably went on some glorious adventures (this is the stage he's in at the HQ lobby atm) Eventually got stuck in Technomagic land and was transformed by Elmorium. Did some shit on the Technomagic world, got caught up in the Death Cult's kidnapping of a Mystan elder who happened to be his friend and fought with one of their agents to a stalemate. Pursued the Death Cult and met Schradinger's character, went on a very short space adventure, caught the Death Cult at their big tower, went in and rekt face, found the Death Cult and was convinced by the Elder they meant no real harm (questionable, Clockwork probably would have bitchslapped them for the lives lost in Mystan) then everyone kind of cut off posting with the Clockwork Man stuck in the Death Tower, presumably surviving the Angar Ryllan invasion immediately after.
More tenuously linked to the multiverse are the world of the Ramor and Felenr, which are both being plagued by wormholes into the web of the Nexus for drastically different reasons.
Metz: Just found out all the mana on his planet is being eaten by Ghourkas.
Ramor: Grent Republic have captured Saanja, possibly planning to convert him and use him as an operative to explore the Nexus, if IN is interested. Jok is currently trapped in the weird universe Innue's tournament is set in, and presuming he survives will return to report his findings.
That's all my lore, might dump it in the Multiverse thread if that's what you're supposed to be doing, but who knows.