[quote=@OliveYou] I'm thinking of a more team system instead of the isolated pairs that I thought of in the beginning. there would still be birthed/mechanic pairs to an extent, but we would all collaborate with each other in battle.[/quote]
I completely agree with that idea.

As far as team roles go, I'd see Nightmare as the Blocker, standing at the front and soaking up as much damage as he can. His shield and armour should help him out quite a bit with this task.

Trey would be a Flanker, using his speed and mobility to reposition rapidly but often leading to him being separated from the rest of the party for short periods during combat.

Trixie would be the Jinx, deploying drones to harrass and distract enemies, as well as capitalising on any moments of opportunity to cause damage.

Kiki would be the Mastermind, using her abilities to both keep track of the battlefield as well as disrupting enemy technology, keeping them from bringing their own support in and disrupting their plans.

And Fiore would be our Support, providing medical aid and keeping an eye on the team to ensure no-one is left unassisted.

This means we really need a Blitzer right now, someone who can provide steady damage to our opposition, as well as occasionally blowing large craters in the landscape. Trixie could be repurposed for this role, depending on how well she can scavenge materials to build fully operational battle bots, but a character with dedicated heavy firepower or close combat capabilities would be perfect.