Round 256: Nimbus breathes, and FHM dodges it, but takes 3. FHM has 33 HP left. FHM sits there, still apparently waiting.
Round 259: Nimbus breathes for 6. FHM has 27 HP remaining.
FHM makes that sound again, dealing 8 points of sonic damage, but Nimbus avoids any other harmful effect (Fort save 18). Nimbus has 41 HP remaining.
Round 262: Nimbus breathes for 5. FHM has 22 HP, and sits there.
Round 263: Nimbus breathes for 5. FHM has 17 HP.
Round 267: Nimbus breathes for 4. FHM has 13 HP.
FHM makes that sound for 3; Nimbus avoids other (23 Fort save). Nimbus at 38 HP.
Round 271: Nimbus breathes for 5. FHM has 8 HP.
Sound for 8 (Fort save 23). Nimbus is at 30 HP.
Round 272: Nimbus breathes for 5. FHM has 3 HP.
Round 274: Nimbus breathes for 3, and FHM is at 0 (is that better?). FHM is destroyed. Nimbus is at 90N100E20Z, heading north, and can breathe again next round.
Round 274-275: A cross between a lizard and a fish, with a human-like head comes in, and flees after being breathed on. Nimbus can breathe again in round 278.
Round 278: The tiger flees after being breathed on. Nimbus can breathe again in round 281, and is at 100N10E10Z, eastbound, with 30 HP remaining.
Gansk will have to let me know if the next creature can affect Nimbus.