You can also be a boss and walk through the front door and still win it.
Run up, teleport him near your party, gank him and use warlord to gank the nearby melee skeleton (or CC him and ignore him) and then kill the wizard to the right while ignoring the archer.
The big blue dude should be one shotted by the time you fight him if you're appropriately geared for that game plan. Levels don't really matter that much.
My party at the time was double castard, double melee (rogue/knight). Zero gimmicks other than teleport.
Alternatively, you could just phoenix dive and wreck him anyways.
With Rage + Sacrifice of Flesh there really isn't any need for tactics.
Well, you are on a different level from the average player, my friend. This guide was not written for people who take warlord, who use rage, who know about racial skills. This was written for the average pub. The last pub I played in, the preferred tactic (by popular consensus) for dealing with this boss was to have everyone cast a spell at it, and then have our necromancer shackle of pain it while we dealt with anything else. I can't stress this enough - from what I have seen, people simply do not know how to deal with this boss. Not to mention, I am well aware of your notion of "properly geared", and I find it totally improbable. I'm sure it's possible, but have you seen the average player? Have you played a four player pub, where you have but one character with which to beat the game, against all odds? I mean, they're doable with archers, easy with rogues and warriors, but I play a mage. I have to sit back and watch as my party runs facefirst into this boss fight, gets phoenix dived, one-shot, and then it's finally in range for me to CC, while the skeles overtake and violate the survivors. It's almost nightmarish. If this guide helps even one player, I'm glad I've written it. I am beyond a shadow of a doubt positive that that player will not be you, as I am sorry, but I do firmly believe that there is nothing I could teach you about this game. But please, I entreat you. Think of the pubs. Think of them. They need to learn this. The last player I played with was running zombie + necromancer on a mage, and his second character was the red prince with zombie and... I don't know how to say this, but... no levels. He literally didn't level him. He just... Had those plus signs on his portrait, and there was nothing I could do. No amount of reminding would stat him out. No amount of spamming his inventory with warrior skill books would get him Rage or Phoenix Dive. This is the kind of player I've played with for the past 5 days, during my pub runs. This is the kind of player that needs this guide. So please. Think of the newbies.