There's a good chance that there won't be a representative of Osiris at The Tower. And there's a reason behind this: People thought that, at the start, Osiris was a Tower faction, like New Monarchy, Dead Orbit and Future War Cult, but Bungie said it wasn't true. [spoiler]Osiris was the name of a warlock who was exiled from The Tower because he apparently came 'too close' to understanding the Vex. While I'm not one for rumours, The Trials of Osiris could be a homage of sorts to him.[/spoiler]