Gul'dan's keen eye allows him to cast Fel Scythe when any additional target stands within 2 yards of his primary target when attacking.
Fel Scythe cleaves at targets for 167.9268 Fire damage, divided amongst targets within 2 yards, consuming all of Gul'dan's Fel Energy, increasing in damage by 5% for every point of Fel Energy consumed.
Each successful cast of Fel Scythe grants Gul'dan Fury of the Fel.
If Gul'dan ever reaches full Fel Energy, he immediately casts Fel Scythe at his primary target.