Sometimes, one can't blame Chris Claremont for using mind control.
When Claremont took over Exiles, he was handed a bit of a conundrum regarding long time, shapeshifting member Morph. Y'see, he wasn't exactly the same, fun loving miscreant everyone had grown to love.
The Exiles finally came up with a way of defeating Proteus, by using B-Mod technology from the Squadron Supreme reality they visited during their hunt. 'B-Mod' is short for 'behaviour modification' and that's exactly what happened to Proteus Morph when he donned a crown that was secretly lined with B-Mod circuitry. It essentially reset Morph's mind, returning him to his old self, while Proteus aspect was rendered dormant... Bottled up, ever ready to resurface.
During Chris' run on both Exiles and New Exiles, the threat of Proteus reemerging was repeatedly hinted at. The notion of your teammate effectively being a single moment of clarity away from turning into a genocidal omniversal overlord gave everyone the shivers...
Yet, everything seemed pretty much okay, until the events of New Exiles Annual # 1. Morph was put in charge of the team as they responded to a distress call from an alternate Earth specifically asking for their assistance...
As it turns out, it was Valeria Richards, the daughter of Reed and Sue Richards they had encountered during one of their earliest missions. This Valeria was pretty similar to the Valeria that Chris introduced during his late 1990s Fantastic Four run. This meant she possessed many of the traits a typical, young Claremontian leading lady has: acting both chipper and delightfully snarky, with a genius level intellect and amazing powers to boot.
How amazing, you wonder? Well... after their initial encounter, Valeria constructed a means of following the Exiles on their adventures across the omniverse, even travelling to the alternate Earths they would eventually visit.
However, for some unknown reason, Valeria arrived early on a world that also happened to be in the grips of The Maker, an alternate reality Shaper of Worlds who had gone mad. Instead of longing to improve worlds, this one actually got his kicks from causing as much destruction as possible. In this case, by challenging five supervillains to outdo themselves.
Valeria called in the Exiles to set things right. And so they did, defeating crossdimensional counterparts of Doctor Doom, Magneto, Red Skull, Green Goblin and a Baron Mordo/Dormammu mix who wasn't beyond using mind control, by the way.
Making short work of the five baddies meant the Maker was forced to deal with the team himself. Teleporting everyone to his base on a second, smaller Moon orbiting Earth, the final confrontation got underway just as something went wrong with Morph....
For some reason, Proteus was starting to break free from his mental prison, but the Exiles were a tad too distracted to notice. Psylocke and Valeria combined their telekinesis and force field powers to protect everyone from the Maker's fury... But simply throwing up a shield doesn't save you from a being capable of reshuffling existence at a whim.
Ow yeah... the bad guy has managed to sink his claws into one of the good guys... We all know what happens next, right?
Yeah... that's the Shaper of Worlds for ya... mad or otherwise, he is always at the ready to reshape and remold everything you once held as true about yourself or those you trust. Speaking of reshaping those you could trust, Proteus finally makes his move...
"There's someone else inside my head!"
Well of course there is, Morph/Proteus! After all, this is New Exiles, the comic in which Chris Claremont had no less than 4 main characters go through the exact same thing in the space of 18 issues. It happened to Cat, Sage fell prey to it as well and even Psylocke had to fight her way through it... So why not you?
One might simply dismiss this as a case of lazy writing or even call it a blatant copycat approach to character development... But consider this: maybe Claremont was going for a motif...? Perhaps he was trying to do a subtle study on how everyone deals differently with their less than desirable traits and urges? Do we vehemently deny and cast them out, like Pylocke did? Do we let them overwhelm and change us, like Cat? Or do we accept our darker sides, becoming more powerful in the process... like Sage and Morph...
Ow wait, did I just give away the ending?
"You're not alone inside this head, this body, this soul".
Defeated by the Shaper, sorry Maker, Proteus retreats into his own mind and finds the spirit of Morph there. Kevin Sydney happened to be alive and well... or something... and grabbed the chance to stage an intervention of sorts. "I can sense all this supervillainy stuff isn't making you happy... let me help you learn to help yourself".
Before those lines cause all of us to burst into a rousing rendition of Simon and Garfunkel's Mrs. Robinson, let's see if Mister Proteus took the long dead former inhabitant of his body up on his offer...
Oh, right, right... more talking... Guess convincing someone to essentially give up being themselves isn't done in a panel or two. But finally, this happens...
And in a flurry of bright, pink lights, Morph and Proteus become one... Morph's cheery nature washes away the hurt and pain that made Proteus into a supervillain. Just like one appeases an angry dog by removing the thorn from its paw. The new patchwork persona was immediately accepted by the others and all was right in the world again.
Forget the fact he's essentially a lobotomized supervillain responsible for burning through at least a dozen host bodies during his reign of terror across the multiverse... I guess being given a new lease on life in an immortal, shape shifting body is punishment enough, right?
Well, if anything it also made Proteus into Doctor Phil clone, with a similarly annoying accent.