its been 11 months since they released Hogger and although there are plenty of WOW heroes, I would suggest making one of the alliance leaders - Prophet Velen. The problem is that there is already Anduin as a Priest healer, so the only spec that Velen could have is a shadow spec, which is quite inacurate. But basically the gameplay of this hero would be similar to gameplay of shadow priest in WOW. Velen would be based on placing Dots like vampiric touch and shadow word pain. He would have renew or barrier as self-defensive spell. Ultimate talents could be whether mindblast for single target burst or Mind shear for AOE dmg. Hero trait could possibly be shadow form which would boost all shadow dmg / reduce incoming dmg for few seconds.
class strengths + : sustained dmg (casting dots on every target), self-sustain (healing from vampiric touch and renew/barrier)
Class weakness - : basically no control (if not adjusted with some talents like psychic scream or silence), lack of burst ( without mind blast, this class would not be able to burst much), lack of mobility (most of spells would have cast or channel time, which would require Velen to stay on place)