Dwarfstar

Sylbert Rundine  is a psychotic serial killer - he was a student at Ivy University, where he stalked the dormitiries, racking up kills. He eventually stole a Bio Belt which gave him powers similar to the Atom.

Dwarfstar is the name that Sylbert Rundine used after he got the Bio Belt. A psychotic supervillain, he was primarily responsible for killing the fourth Atom (Ryan Choi). Although he was paid to do the assassination by Deathstroke, he loves killing (and hated The Atom) so much that he would have done it for free.