Actually, unless I'm mistaken the Zandalar trolls are the ones that appeared for Zul'Gurub. you gain rep with them by killing things in ZG, and doing quests for them in there. So, I don't think that's gonna be much use for you until you hit 60 with your Warlock. >.< I've searched around for a mana regen potion myself in Alchemy, since that would be kinda handy. Haven't found any though apart from the two that have already been linked. Guess I'm just gonna have to rely on Innervate! ^.^