Warning, there might be a few spoilers so just be warned.
Having looked at the lore behind the the man that went by many names; Wu Ming, Germaine, Eli, Drifter. Having been resurrected in the dark age, his life was hard, going days without eating just to die of starvation and being brought back by his ghost and still being hungry. (The Man with no Name)
He says he hates ghosts because they just bring you back just to save their own skin(shell?) and that Guardians shouldn’t trust them for it based on his experiences in the dark age, a few desperate enough for just some blue engrams(Drifter tapes)
Everything he has done is to prepare for something, lying and cheating to get what he wants, information or otherwise.
So, Guardian, what is this lightbearer to you?