Honestly anyone who has doubts about these illusions going to waste by not being attainable in some fashion- go do the mission. Make sure you choose Mithanial Marr... that model is just astounding... the details... it's incredible. The illusion is already in game, the work is done, just make it usable! I'm actually curious- is he in game anywhere else or is that the only time you see him? The rest of the gods I've seen in game- including Soulsek Ro who is in (I think valley?). The other gods you can see in the plane of Time.