I had a way better explanation. This is a world of magic so I'm not looking for any real sense of logic. My original concept for the manaegis was that the armor os entirely made of mana and is summoned /dismissed through the nether. In order for it to bend the armor simply phases through itself as the user needs, preventing a need for the seems altogether. Though it would take great skill to control it is possible to do so, with the armor adapting to what's needed of it. 
Etc