I haven't fought him yet, but I'm curious about this:
5 Call for Aid in a chain 7 technique, which can evade <range> melee, ranged (and others?) damage.
I ask because here's the quoted example:
You catch him with an explosive round. It deals 18 damage, but a complex pattern of green light appears, holding back the attack.
The doctor raises his hand into the air and shouts "Please! Aid me!" Nothing happens apart from the sensation of being watched.
The combat text says that nothing happens, and I notice that Call for Aid is right after the chain 6 Distant Claw. Could the green light holding back the attack have come from that?
EDIT: I think I've been spending too much time hacking, where doing something tends to have it effect in the following round. In regular combat things are generally instantaneous.
But, I've got another thought. His attacks produce green light, right? And in this game, what does that make you think of? Well, it makes me think of the Fae. Has anybody with Fae Sight tried to talk to him? Maybe he attacks folks aligned with the fishmen and would be friendly to somebody who's aligned with the Fae.