"I have a dead man waiting for me to bring him back." Senku responded simply. "He wouldn't be the first, but unfortunately his death was inevitable. He was attacked by someone he trusted and regardless of the surgery I performed on him, without modern medicine, he succumbed to sepsis, so I put his body on ice. It's a gamble."

If it didn't work, then Tsukasa was dead anyway and there was nothing he could do about it, but if it did? They'd have their strongest warrior back.