Ultane is the final boss in the Tier 2 Grim Awakening raid. If you have managed to get this far then Ultane should be killable. I will not suggest he is easier than Salverola, but he is not impossible. Just pay attention to the mechanics.
This video demonstrates a perfect run resulting in the Ult-imate achievement; Defeat Ultane without a player dying. I am playing on my Cleric as purifier. My primary focus is keeping the group alive. A random player will get a debuff (red on my frames) that will kill him pretty fast. My shields will almost completely mitigate this damage. Other than that I try to heal my ass off in the kiting phase to assist the raid healer and bard. When needed I use Flame of Life, just make sure you have it avaiable in the final phase!
If you have any additional questions feel free to post them in the comments. I can write down a proper strategy summary if requested.