Kangaxx... ... the only opponent to succesfully instill fear into me, until I learnt how to deal with him. In my opinion, he puts up a better fight then Irenicus.

I will split this into two parts, the lich part, and the demi-lich part.

P.S.: Pre-battle preparations,
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Cast Remove/Resist Fear on your party.
Haste optional.
Make sure you have one Protection from Magic for each of your melee fighters in their quickslot.. There're only 2 in the game, so choose who's gonna face Kangaxx.
Cast Melf's Minute Meteors for all your mages if possible.
Get someone to wear Ring of the Ram( it's possible to get 2, but 1 can be enough).
Try to memorise Spell Immunity for all your mages.
If you have a fighter with proficiencies in Mace, equip him/her with the Mace of Disruption.

Lich:
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Before summoning him, spread out your mages and ranged units so that they are not within range of Kangaxx's Symbol Spells( Fear, Death and Stun), and Sunfire. The overlooking platform in the tomb is a nice spot for 2 mages to cast spells at Kangaxx without fear of being in range of his area of effect spells.

Try to have the spell True Sight activated at all times, this will allow you to target him with spells, and remove his illusions.

Make sure you have some disabling spells, Ruby Ray of Reversal and Khelben's Warding Whip are very very good for removing his Spell Protections. Secret Word can be used too, but it's not really necessary.

Abi-Dalzim's Horrid Wilting is a nice spell too, try it out, you may get lucky and wipe him out in 1 or 2 hits.

Now that you soften him up, hit him hard, he should fall soon if your fighters are successfully hitting him for damage( disrupts his casting).

Demi-Lich:
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Kangaxx starts sneering and boasts to you how he's oh so powerful. http://www.tgeweb.com/cgi-bin/ubb/no...miles/wink.gif As soon as possible, before he engages you, do the following,

Use the Protection from Magic scrolls on your fighters, cast Spell Immunity for your mages, choose Abjuration.

If all goes to plan, he starts casting Imprisonment on your fighters, but the spell will be ineffective. http://www.tgeweb.com/cgi-bin/ubb/no...es/biggrin.gif While Kangaxx is distracted, shoot the Ring of the Ram at him and pelt Melf's Minute Meteors at him. Oh and if you have it, one of your fighters should try swinging the Mace of Disruption at Kangaxx.

Good luck!

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If not a Sorcerer, then a Paladin.

http://www.bg2station.de/artikel/media/dragon02.gif

Use spell imunity abdjuration or something like that on one of you party members and make kangaxx attack him..then you go hack and slasch him with +4 or better with everyone else

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I'm a protector of good
a seeker of truth
a symbol of light
a man of honor
http://www.interplay.com/bgate2/imag.../DualWeild.jpg