Been solo'ing Kael for Ashes since Cata. 70 kills across all toons + a handful of kills from BC. No luck and getting frustrated.
Considering leveling up a couple more toons just to have more shots per week at the mount.
His name is Blerg... and he has being named such because Blerg has caused many of us a great heart ache when farming for over many months.
I wish you luck on your quest for Blerg... and may the celebrations be huge when he finally drops!