I did some checking, and it looks like we may be adding too much to the modifier from the spell:
Code:
[COMBAT__PROCS] Xamlagar: Proc chance 0.11 (0.07 from bonuses)
[COMBAT__PROCS] Xamlagar: Spell proc 0 failed to proc 3129 (10.7125 percent base + 100 percent spell mod = 10 percent chance)
[COMBAT__PROCS] Xamlagar: Spell proc 1 procing spell 6908 (10.7125 percent base + 500 percent spell mod = 53 percent chance)
[COMBAT__PROCS] Xamlagar: Proc chance 0.11 (0.07 from bonuses)
The first one is
Call of Sky, which has a modifier of 0 (so it should be 100%). The second is
Spirit of the Puma, which has a modifier of 400 (so it should be 400%).
I'm just not really sure if it would be better to put the check in
Mob:TryWeaponProc() or
Mob:AddProcToWeapon() rather than
Mob:SpellEffect().