Spengler will take the shot(s): first with polar ray and stunning, then turning right and using greater dispel, chain lightning, hold monster, and temporal stasis.
Since Spengler delayed instead of readied, I'll let him fire the first two rays, then let Bleep finish his turn, then let Spengler finish the rest of his turn.
Both rays hit. Bleep takes 45 cold damage, but is not stunned (38 Fort save). He has 335 hp left.
Bleep will burn Spengler (or will she?) with a flyby attack, then take refuge landing in her starting position. The path will carry her off the south side of the roof, which may expose her to more stray shots. 70n65e is as far E as the flight path goes.