Oh. Did he not know about the alternate universes thing?

"I have also conversed with the Karkat you speak of, I'm fairly certain," she returned. The mention of "pure blood" made her wonder, but she was pretty sure that if there was a third Karkat in this tower, one of the other two would have told her. "My Karkat and I come from a doomed timeline. The hemospectrum is not aligned in the same way as the hemospectrum of the timeline that most of the trolls here come from, I think."

There's a momentary hush, before she ventures, "Is your name Eridan?"