I'm back in Sigil after beating Trias. (boy did this game take an unexpected turn towards heavy, not to mention cumbersome combat) Can I do better equipment-wise? Here's what I've got:

TNO - Mage
Weapon - Dagger of Celestial Fire
Eye - Kaleidoscopic Eye
Earrings - Amber Earrings
Tattoo 1 - The Number of Ku'u Yin
Tattoo 2 - Tattoo of the Lost Incarnation
Tattoo 3 - Nothing
Chest - Nothing
Ring 1 - Aegis of Torment
Ring 2 - Ring of Thex
Hand - Nothing
Wrist - Intestinal Phylactery

Morte
Weapon - Teeth of the Fire Drake

Dak'kon
Weapon - Streaming Blade (5-20 +3)
Chest - Dak'kon Zerth Armor
Ring 1 - Displacer Ring
Ring 2 - Displacer Ring
Hand - Nothing
Wrist - Dread Bond
No tattoos

Annah
Weapon - Mark of the Savant
Earring 1 - Obsidian Earring
Earring 2 - Chained Teeth Earrings
Chest - Jerkin of the Brazen Rogue
Ring 1 - Serpent Ring
Ring 2 - Serpent Ring
Hand - Nothing
Wrist - Spider Bracelet
No tattoos

Fall-from-Grace
Weapon - Touch
Earring 1 - Fall-From-Grace's Earrings
Earring 2 - Stinger Earring
Chest - Bodice of the Godless Priest
Ring 1 - Mempa's Biting Ring
Ring 2 - Ring of the Traveler
Hand - Nothing
Wrist - Nothing

Vhailor
Weapon - Heartgrinder
Chest - Mercykiller Armor
Ring 1 - Ring of the Traveler
Ring 2 - Ring of the Traveler
Hand - Nothing
Wrist - Nothing

For the endgame focus on giving TNO the best equipment. The other equipment is quite good, but definitely go to Fell and buy 2-3 tattoos for him, which tattoos are the best available depend on your character stats and how you've played the game.
Dak'kon and Annah will benefit from tattoos too.

I ended the game at lvl 13. Sure I got brutally raped by the wraiths in the Fortress of Regrets, and found 2 of the three major bosses incredibly difficult, but I had the Blade of the Immortals. That's really all you need. However, you might want to buy a million health items for when you fight your paranoid self.

Or just don't fight him at all! ;)

I hate those damn shadows. Had to run around the whole time. A good tip (from this walkthrough is to have enough cloudkill spells/items, those kills them immediately. Only problem is, I could seldom summon that damn spell :/

Was about to ask why you killed Trias, but saw that you had Vhailor tagging along. Guess that answers that question. ;)

Strictly speaking, though, it is entirely possible to make it through the vast majority of the endgame with only getting into one fight. All other fights are optional, so don't feel the need to try to take on everything; you do have other options, namely running and *cough* alternative dispute resolution.

Negative Plane Token is a huge help in Fortress of Regrets. Just put it into quick use slot and use it to paralyze True Shadows. Be careful because it has limited amount of charges even though it is not mentioned in the description. I could usually kill one while the effect lasts with Ravel's Nail (or whatever it's called). Played as a Mage and did everything to conserve my spells for something more nasty...which never came.

Well, except for the room with the statues. Then again, since I had been saving my spells as well, it didn't last too long after I let a few choice nasty ones fly.

I didn't think of using the Token as an item - thanks for the tip though, will surely come in handy next time!
What saved me was that I bought a "....Mirror" and when I got surrounded, I used it to inflict some quick damage on them (though it also has a limited number of uses, of course!). Also a good spell for that is "Balance in all things". Very good for a mage when doing the "proper" Dreambuilder quest, too;) (the problem with the Shadows is, they're to quick. Can hardly conjure those spells on time). Because everyone says that all the time I was expecting a game with a low amount of battle. But there thousands upon thousands of thrash mobs :D Good thing you can run like hell most of the time!

The bits in Sigil are generally pretty light on combat. Things crank up once you leave the city, and the combat becomes more prominent, along with all the unfortunate problems of the Infinity Engine. Thankfully, by this point most parties are of a high enough level that the combat issues aren't felt as much due to the fact that you are more than likely outclassing the enemy by that point. The endgame can be fought through, but the game flat out tells you that the smartest thing to do would be to run your ass off while you do what you need to.

Curst prison and Carceri were a real chore for me in terms of combat. Those two were low points of the game imho. There is also UnderSigil but that area is entirely optional to play. Baator can be combat heavy, but only if you want it that way. Otherwise just stealth through it with Annah.

Fortunately, I was at a high enough level when getting to those locations, so I didn't really have that much trouble, to be honest. I think the best strategy is to gain the highest level you can and then get out of Sigil (although of course, the grinding...:/ Just didn't have the time and nerve to level myself up in UnderSigil. Or...the other place).

And yeah, running was the best option in the endgame. Wonder how'd it be with a level 30 char, though. What's the max level, anyway?

I was at level 10-11 when I got to Curst, and 12-13 in Carceri, I think. These areas weren't hard for me, they were just tiresome. So many guards in Curst prison to kill and in Carceri monsters would just spawn endlessly, forcing me to deal with them every step of the way. By the time I got to the fortress, TNO was level 14 and gained another level in the antechamber for killing True Shadows - I killed them all, not counting those that would appear later. Merging with incarnations and using the Bronze Sphere boosted me to level 25. And that was my final level.

I could have gained more, but I never went into Modron maze (never got Nordom) and didn't do much of UnderSigil.

Well the XP cap is 999999999 so... yeah, hell if I know what level that translates to, but I'm pretty sure noone has hit it.

I was level 26 right before talking to the End Boss, almost 27. Think I even leveled up another level during subsequent dialogues. And I went for Nordom (I...oriented myself after some walkthroughs, wanted to get the most out of this playthrough, since it'll be a long time before I'll get to do another playthrough...).

Yeah, a bit hard to farm for EXP when you need millions to level up :D