The reason why Achilles came here to start with.
Amos!
The one that had nearly cost them their lives multiple times.
It was a loose end that Achilles would not leave alone as the top of a transparent crystal vine quietly snaked over!
Achilles could feel the tumultuous emotions. The fear and sense of regret that the impulses of Amos had.
It was hard to guess this was the same man bragging about others not even being able to say no to him not too long ago!
Achilles tried to just imagine what would have happened if he was not able to assimilate anything.
If he, even in the best case scenario, was just another normal Advanced Human.
He would still be at Lower Body Modification along with Rose, and with such power, wouldn't Amos have been able to send even a few Upper Tier Body Modification Advanced Humans to kidnap them? To kill him and do whatever he wanted to Rose?