Nameless seer in Tower

My friend and I have been playing for about 10 hours trying to get the Nameless Seer in Tower. In other maps it was pretty quick following the right setup... But in Tower it's impossible, my friend only managed to get it because it appeared in the League mechanics.
And I noticed that next to the shrines, The Envoy is appearing and never the Nameless Seer.... Could it be a bug?