its about 95% crit chance without taking into account debuffs on boss. the way i play it, i have 0 haste talents and every 2 energy bolts lines up with chain lightning CD.
The only real mythic illidan is the one you face in Nighthold during Mythic Gul'dan. These private server "mythic" fights are an absolute joke. Ascension is probably the worst offender for balancing. Just long, tedious fights, no skill involved.
