I've just finished Arcades quest and after i did he said he was going back to freeside and he was no longer my companion and after i left the Remnants bunker he appeared but in some some power armor and then quickly disappear, I have no idea were he is I've already checked freeside, Lucky 38,and the Remnants bunker but he is no were to be found. Those anyone know were i can find him?

Since he kept the armor, I believe you'll see him again at the battle for the dam but you'll have to look for him. He's wearing it. I saw him in the Visitor's Center. I was sad when he left as a companion.