If you're referring to Ephidel, the male morph from the first part of the game who dies when the gate is opened, I don't believe he has any connection to Nino. He looks kinda like Erk, who is a possible A-level support romance for Nino... but I don't think Ephidel has any ties with Nino.
If you mean Jaffar, he is NOT one of Nergal's puppets. I mean, he's a loyal henchman, but he's not a constructed creature like the morphs. He's just a disturbed human, who falls in love with Nino. They have a very obvious A-level support romance, and you must save and recruit Nino and then use Nino to recruit Jaffar.