Which hero in all 3 of the series would have wanted to seen in s3, mine would have to be:

Hana Gitelman, we didn't see much of her at all
Candice, they shouldve shown her ability more like making illusions of like so many of herself.
Monica, her power and character is sooo awesome but just used and abused like many other heroes
David Pine, the metal fists guy, his power was awesome
Micah, isnt he a technopath? they shouldve like made him make hiz own machines and stuff
i wouldve liked 2 see Barbara, like her and Tracy meet and stuff now that Niki has gone

Well if I had to choose 1, it would be Monica. She was an awesome character.

Hana is now deceased. Graphic Novels. As is Candice. It's actually Danny Pine and he did appear in Season 3. Make his own machines? Oh, you mean like the laptop he made in Volume 1? It's been confirmed that there are no plans for Barbera as of yet.

Dude, bringing back Monica would be wicked beast! Do you think she could kinda be like Peter and if her body saw someone use their power, she could use it?

Ted Sprauge! without a doubt
Awesome power yet humble character, whose pain I felt!

Also Charles Deveaux (he had to have a power!)

Nope, not even Daphne's or Niki's, it's just muscle memory. I think if she watched someone with superhuman agility, she would copy the move exactly but sprain something.

Ted Sprague was my fave in Season 1, i loved his power, i loved his character, and i loved the fact that he was trying to be a good guy in a dangerous evil kinda way, like when he held the Bennet family hostage to find out what they "did" to him

Bring back Monica plz.
and .. Maya.

NO!

Maya should get out and stay out.
God what an awful character.

monica had potential but im betting after a few episodes she'd get annoying.

Ted, Candice and Claude are very intersting and powerful characters
i have no doubt we will see Claude again one day

And to someone who said they wanted to see the triplets meet, have we seen Nikis dead body?
because if not i wouldnt put it past her coming back.

Yes, we have seen Niki's dead body. Remember the episode where Tracy went to Monica's house to find out more about Niki? She met Micah there and she opened Niki's coffin if I'm not wrong. Surprisingly, Niki looks great even after being blown up.