quality potion of rising force,
you need that or levitation to reach the ledge in tukushapal where the deadric face of god is located, the maze is referring to the maze that you have to complete to get to the tomb, and the halls of the dead refer to the undead inhabiting the maze, the weapon of the saint is storm kiss. very good riddle, had me thinking for a while haha
All *almost right except for the potion part :S
Realize that according to the riddle you havent needed to go up yet so a rising force potion you would not have needed at the "present" point in the riddle.
The "great magical potion" is kind of a satire to what the "potion" really is.
*Another Edit: Actually the "weapon of a saint" was refering to the daedric warhammer besides the daedric face of god as an allusion to "Veloth's Judgement"