What Year is Warren?
Warren's clearly not a freshman, since he wasn't at power placement. He also seemed to have his table in the cafeteria pretty well staked out. Was he a sophomore, junior, or senior?
Also, Boomer calls him Hothead, which appears to be his "hero name". This isn't made clear since we were only told that sidekicks don't get assigned a name until graduation. I more or less assume that upper class heros get to choose a name. However, no mention is made of when/if hero students get to do so. Will, Gwen, and Penny are only referenced by there names, whereas Lash and Speed are only referenced with their aliases. Gwen's the only one specifically stated to be a senior, but the others weren't at power placement so they aren't freshmen either.