Caos can breathe next round, and the other dragon looks addled (rolled 12 Will save), but still takes an AoO, missing with bite (rolled 20).
Round 429: OD is waiting for Caos to come down so it can bite him, making strange growling noises.
Caos breathes a gout of acid, damaging OD 21 points. OD has 76 HP remaining.
Round 430: OD makes more growling noises.
Round 431: OD flees the arena. Caos can breathe this round, and is at 60N80E20Z.
A large biped resembling a lean, muscular human comes into the arena to 30N100E holding a large rock, with a bag and a stone greatclub at his side. He has gaunt facial features and deep-sunken eyes under a bald head.
He throws the rock at Caos, connecting (rolled 30) with brutal force, inflicting 22 points of damage. Caos III has 79 HP remaining, and is next in round 431.