"I'll go." Your girlfriend walks up to the machine.
"Wonderful." Dr. Terrific walked up to a control panel, the spandex of her suit squeaking with every step. "Now, if I may explain how this machine works. Everyone gather around, but not too close."
You could hear the Custom-O-Matic warming up as Dr. Terrific continued her explanation. "This invention of mine was intended to solve a serious problem. What if a hero was killed or injured to the point that they could no longer protect us? The answer was simple. Create a process by which said hero's powers and appearance can be transferred into a new body. Let me make this clear - this is not some sort of demonic possession ritual. Anyone who goes through the Custom-O-Matic is in full control of themselves. However, they must be pure of heart and willing to serve in place of their predecessor."
She then walked over to your girlfriend, holding a small device. "Here are the genetic profiles for every member of the Terrific 4, including myself, as well as several other heroes and heroines affiliated with the Fellowship of Watchers, the Teenage Terror Brigade, and the Guild. Select one and let me demonstrate my machine in action."
Your girlfriend picks...