Dennis actually looks amusingly apologetic.

"Joking, just taking a bit of the piss out of ya, promise." He figured from the way Senku was talking he didn't intend for him or anyone to die, still good to hear him say it though.

"But why would you wanna figure out how to sever the tether thing? If people can come back cause of it? Sounds like that's better for us." Dying is typically a permanent thing, bud. He'd know. He's dealt with it enough in his short life.