He meets up with them disguised as the Fly King first at the Southern defense line then when he meets up with the Mad Emperor and eventually, when it's getting towards the push to defeat the Goddess he has to reveal his face to garner their support. I believe he did not show his face to the one with the black flame wings after he rescued him from the 13th batallion, he did show it to the guy who could summon a minigun and was about to put his hands on his waifu and eventually to the Takao sisters before he confronts the deluded king vessel. He doesn't really care enough about the background characters to hold any hostility to them as they're still useful in his revenge effort.