STORY 

Backstory

Elliot and Kevin were born in the same hospital, at roughly the same time, and since Kevin's mom helped Elliot's mom with her panic and insecurity due to some complications, the two basically grew up together and were best friends throughout their childhood.
As Elliot grew up, he realized he was a boy and went to Kevin for advice, not quite knowing the terms, but knowing full well how he felt. Kevin, who knew immediately what was up, took Elliot to his bigger sister, who was trans herself and managed to set Elliot's mind at ease and explain he wasn't alone. It meant a lot to him, especially when his family didn't react quite as kindly and understanding as Kevin's had. Thus, he has always been closer to Kevin and his family than his own.

During their middle school years, Kevin befriended Nancy, which first didn't sit too well with Elliot, dreading she was going to take his spot as Kevin's best friend. But after a lot of back and forth, he ultimately realized that Kevin considered him just as special as Elliot did with him, and that nothing about their friendship would change just because of other friends - even if this one had super cool powers, while Elliot had none.

Having JC join the friend group didn't bother Elliot at all, and when, eventually, Alice joined the group and team, he had already become accustomed to the steady growth and change of their friend group, and has become confident enough in himself and Kevin to know that Kevin won't just drop him out of nowhere.

Elliot doesn't yet know what he wants to do with his life, only knowing he wants to work with AI, possibly robots, because that's the one thing that has always fascinated him. He enjoys being useful to the team also, and possibly wants to do something that will allow him to make more gadgets for them and possibly other superheroes in the future.

The whole thing with the Tinker doesn't interest him much, though he can't deny something about the guy and his actions just don't add up. If he truly steals from those companies, then why are there never any records of what was stolen? Why are there no more lawsuits once the situation has calmed down a little and lost the public's attention? What is Tinker truly up to? Somehow, nothing makes sense, even less so because Elliot never seems to be able to find anything on the guy, anywhere. Which is weird, because Elliot can find anything.

Code Name "Ace"

Elliot doesn't have a superhero persona, because Elliot doesn't have any powers. It's something that has bothered him for a long time, especially when his best friend suddenly found other friends with powers just like him.
But eventually, Elliot came up with something different: When the team is out and about on their 'missions', Elliot goes by the name 'Ace' and uses his computer to track them and their progress and give them advice, intel and the best escape routes whenever necessary through modified earpieces. He also supplies them with all sorts of gadgets he makes out of remodeled bought stuff.

Hence, he's not exactly a 'hero' like them, but he's doing his part as a helper of the heroes, and knows he has already saved them several times over.