- "I would say no weapons on school grounds. But what is that?"
The Energy Knife was a weapon wielded by a future version of Alex Wilder coming from 2028 to murder the Runaways. He brandished it while attempting to infiltrate Atlas Academy, and notably threatened another student with it while Kwan asked about the nature of the weapon. Eventually though, Wilder was incapacitated by Nico Minoru and the knife was confiscated from him. It eventually disappeared when the Runaways were able to revert Gert Yorkes' death, thus cancelling the timeline the future Wilder came from.