I think the most obvious trio to go should be Senku, Tsukasa and Ryusui. But I really wonder if Senku will be cut out for it. Maybe Chrome will go instead of him? I remember that before Tsukasa was put in the fridge Senku made small talk with him who would he take with him to space trip and he...
Hmm, maybe but remember that Senku went in do it as fast as possible route. They have to get to whyman like as fast as they can and thinking how to build a medusa would deffinetly take way more time than building two way rocket. So either they will change their mind and build a rocked that will...
Maybe why-man programed it so they could self destruct if he send a signal(not nessecary a voice command)? For me the sphere from this chapter looked more like explosion rather than a flash of light. And maybe when self-destructing, medusa send a smal wave of petrification too.
Well but I think...
Quite sure it's not the limit, Yo was petrifited as many times as Gen I think. If we would go this way then Rusui would crumble first since I am quite sure that he was petrifited the most times or at least more than Yo