Undead Priest takes a 5 ft. step towards Xix. Here is its ring of blades damage for the round...
Undead Priest - Ring of Blades damage: 1D6+10 = [5]+10 = 15
The spell hits Kefax, Xix, and, I think, Autar, as well. The wall protecting Autar is only a low wall, not a full wall.
Then, it casts...