I never did understand that 1 round casting time.  I think Gansk's cleric has had his concentration broken twice while trying to cast that spell.
Round 587 (continued)
As Ari flies in, Volkanor takes an AoO and a readied bite, hitting both times (worst roll 46) for a total of 48 points of damage.  Ari has 209 HP remaining.
Ari bites back (rolled 58+5-5=58) for 21+10-5=26 points of damage.  Volkanor has 423 HP remaining.
Volkanor leads off round 588.