In the City Gate District is an inn called the Crooked Crane. Walk around near the north wall, and a secret door will be revealed. Do not enter. Firstly, cast Non-Detection on a character, or give them the Cloak of Non-Detection. Then cast Improved Invisibility on them. Get that character to head down through the secret door. Open the chest next to the lich, and take the sword. Don't worry if the lich casts time stop, as he can't do anything. Head back up, and identify the sword. It is Daystar, magical longsword. Get your characters to surround the secret door. Give it to someone the invisible character, then get them to go down to the lich. Run up next to the lich, and use Daystar's Sunray ability. It will do massive amounts of damage. Then, just stand there, hacking away at the lich. Vouila! Instant 22,000 xp, some nice items, one of the most useful swords in the game, and without any party members getting hurt.

You know, I never paid much attention to the Crooked Crane once I realized that all that was there (in the unmodded game) is Aulava and Tiiro. In my first ever game I found the secret door but I couldn't pick the lock so I left. Can you open it with Knock or some such?

Nice, I never thought about stealing Daystar and using it against the lich.

Any decent thief with ~80 points in open locks should be able to pick the lock. Knock will also open the lock.

That lich is soo cursed, he almost always manages to give me headache!

However I did discover a bug, have all of your party (except you) move to the upstairs where Aulava and Tiiro are, and let them wait. (it is not a party required area) Then ONLY YOU enter the lich's room, for some reason Lich does not see, talk, or even attack YOU! All he does is to sit there, taking damage and die. Needles to say, it can not even be considered a battle, rather some practice.

I do not know this will happen in your game too, but give it a try! You may be suprised!

What is about Crooked Crane inn after installing UB?

I don't see any different. hmm, is that related to circus?

@Ruin Ehwazehs

It is related to the circus and Kalah.

You also lose some rep if you tell the kids to let their love run wild and free, if I remember correctly. You go downstairs and someone tells you they've been off killing and stealing and says "thanks a lot!" I'm fairly certain this didnt happen in the original game, although to be honest it's sometimes hard to pinpoint the small differences.

Those two kids were in the original SoA.

What kids? I don't remember and kids...... what are they do with lich?

The kids are in the top floor of the Inn. They have nothing to do with the Lich.

Oh, and I believe that their running off to a life of crime dialogue is in the unmodded game.

JSBB is correct. In one of my early unmodded games I told them to run off and everyone got angry at me.