Eaon's eyes scanned over Senna in the moment when she started throwing insults around? Him? Trash? Okay whatever she says, Eaon was sure the eight hundred year old Swordsman who'd been doing her job since the last Captain departed and before she got the position didn't know what he was talking about. She'd learn, she might not like it, however she would learn. Besides Eaon didn't actually need to say anything else, she'd proven all of his points the moment she'd decided to start arguing. Rookies would be rookies though, maybe in a few hundred years she'd learn. Besides Eaon tried not to judge people based on the often wrong first impressions they made.
Eaon did listen carefully to the new comer that apparently inhabited Captain Proto's body. Clad in armor and his voice different Eaon wasn't quiet sure who it was they were now talking to, however the lack of change in Proto's noticable Reiatsu made him believe that it was at least the same body, though perhaps a different entity. Eaon was not Division Twelve and the ideas of sciences that may explain what had happened were beyond him, however this new entity did make Eaon think about somethings.
Eaon was one of the best swordsmen in the Seireitei, known for being a swordsman who trained Shinigami without actually having been a Shinigami himself. However if they knew that most of his training was not in a dojo or with his master but rather as a hired assassin by the Police forces of the Rukongai Eaon really wondered what Senna would think then. Technically what Eaon did was illegal, a weapon used in times of bloodshed to become the means of an end. An end that was "lawful" however also illegal. Perhaps it was also the reason Eaon never accepted a Captain's position, not because he felt he lacked qualifications, but because he still viewed himself as a sword, and a sword does not deserve the privilege to wield itself.
"I was a doctor before I became a swordsmen, I wanted to help people, however once I picked up a blade and spent some time with it I could kill ten men before they could scream, even before I was a Shinigami. I enforce the laws because there are others like me probably, and they will not have the philosophies I follow, and thus will choose to kill and take power when available to them. That must be prevented." Eaon said answering what he still assumed was some form of Proto's question. Perhaps it wasn't the answer he wanted, however it was the truth. Eaon thought people who could kill shouldn't hold power, and those with power shouldn't know how to kill as effectively as Eaon could, because if both came together, all could end with a new found form of efficiency. Besides not all enforcement meant someone had to die, and Eaon rather liked thinking he could make a difference here and there.