The aegis Reasoning edit: kabr made the aegis from... Himself, pretty much and "I once had many brothers and sisters" could have been referring to his fireteam The overlord is of course Atheon "I have found pieces of long lost memorable family, but am still looking for one whole piece. " this could be referring to the rumours of praedyth, and all the other guardians on his fireteam. "I am still looking for a wielder." This is the aegis needing someone to hold it