I wouldn't waste that item if you're referring to the Blizzard potion. Use Summon Undead and you'll be successful in Haunting easily.
With small stats you won't hit Haunting with Book of the Dead, headcase. With Battle Fury even a 1 COE Hansel can hit Haunting.
I agree with raichu, mithril shouldnt be wasted on ebs, though at the same time now its on sale... Hmm! I would say use the summon undead instead, or book of dead half and undead half. Just think of the costs
He's talking about using the spell not pot. With the spell the 45mil attack will let you hit haunting easily.
Sorry I forgot I had a L2 Titans Lair on my alt, so 174,084 attack power plus Battle Fury can hit Haunting. Don't waste it doing eb's though, best to save it until you really need it. For wars if you plan on doing any, if not whack away at the Haunting.
I know its not the question asked, but you should be able to use the 7.5 mil or both the 7.5 and 2.5 and get allsuccessful actions
I wouldn't waste mithril on ebs, and holy wrath will guarantee all but the last 2 hits with one COE, all if you're lucky