This is how I did it in Chapter 2 without much damage, except the self-inflicted:
1) Get the ring of gaxx and Shield of Baldurian first.
2) Summon spiders or whatever for the distraction.
3) Wand of cloud kill the main room with two to three overlapping each other, make sure the summonings is not hit.
4) Put everyone as far back towards the stairs as possible
4) Use the boots of speed, shield and the gaxx on the fighter to start fight, get fighter back out of shanglar's view.
5) Get as many melf's minute metoer ready (I had 4 mages)
6) Pound the vampire to avoid level drain, then the shanglar's double with the meteors.
7) When time-stop, the summonings should cop all the symbols and die...
8) By the time he comes to you, you will just finish him easy...
Sorcery and Shadow together as one, the arcane and the dark united. Through our knowledge and skill none can stand against us. We are as one, infallible and invincible. The Shadow Mages.