Perseus and Merope have already met once at Castor's training camp, and she would certainly be down for having a morals discussion with him (she's very strongly in the no-kill-nega camp, but is totally fine with force being used. Its a fine line). I think as far as senshi or civ, she would need to know he's merope/carter to really have a deep discussion, so unless you're down for a reveal senshi is probably best.