Sorceress vs. Duriel Edit
It is very likely that a Sorceress will be killed at least several times while dueling Duriel. As such, any item worn proves virtually useless, since they are lost once the player dies until the corpse is reclaimed. This strategy is for Sorceresses on levels 21 or above, by which time she should have several points in Fire Wall and one in Teleport.
It is strongly recommended that the Sorceress casts a Town Portal outside the chamber, since running right into Duriel is something very unfavorable. This of course kills any chance of returning into the town and taking time to refill potion belts and heal herself, but it is very most likely that she will be killed at least once, which empties the belt save the last patch, and therefore it is better to enter the safety outside for time to recast Town Portal outside and face Duriel again.
Fire Wall deals massive damage in relatively low levels. It is best for the Sorceress to have reached at least level 23 (which she is in fact likely to have after going through the Arcane Sanctuary and the six fake Tombs of Tal Rasha), making the Fire Wall at around level 3 or 4, which deals a staggering damage of around 180. Though it is likely to be lost on death, a staff that provides bonus to Fire Wall will help incredibly. Duriel is very strongly resistant to Cold damage, making Cold-based attacks nearly futile other than to slow him down.
The hireling's sole purpose is to exist as a meat shield while the Sorceress stays back in relative safety and casts Fire Wall. Upon the hireling's death, Duriel will instantly charge at the Sorceress, who must respond by swiftly casting a fire wall in front of him (which will very likely damage him due to his size) and teleporting to the other side. She must be very quick on this, since if she allows herself to be struck she will be stunned and yields around 1.5 seconds (that feels like some five seconds) which is more than plenty for Duriel to finish her off. If she has traveled far enough, Duriel may in fact be confused and try to search for her nearby, which can buy her slightly some time to drink potions and half-refill the belt. One round of this is in fact likely to have damaged Duriel severely, taking down his life by around 10% to 15%. However, it must be noted that from the second round she lacks a hireling, which steals any time one would have bought for her.
Continue this Fire Wall and Teleport until either the Sorceress is killed or her controller is quick enough to actually defeat him on the first encounter. If the former, she should take another mercenary as a meat shield and reenter the portal and cast another.
Upon reentering the Chamber, the Sorceress may like to reclaim her corpse before turning to Duriel again, especially if she was holding any staff that boosted Fire Wall. Continue the casting Fire Wall and Teleport until Duriel is finally killed.
Alternative strategies may be using Static Field spell (not 1st level, a few more to have enough range) which really hurts non-lightning immune bosses eating average 10% of his life per blast (assuming he's in range), paired with hasted shoes (+10% is enough). After hitting him hard to 30%-50% of his health (should be about the time your mercenary falls), start spamming Nova or Frost Nova - Duriel will fall swiftly,
Another Strategy, if you have a lot of points in the charged bolt skill, is to use it as fast as you can while wearing increase cast rate rings. You will get more hits this way, and can cast town portal in Duriel's room and use a mercenary to block. Oddly the charged bolts are more effective than lightning or chain lightning or most other skills.
Duriel's unholy aura freezes the Sorceress and her hireling, but does not stop her from teleporting far away. As such, she is more likely to last much longer than any other class. Her spells, especially Fire Wall, are incredibly damaging even at lower levels, making them very effective even against stronger bosses, and especially Duriel who will suffer most due to his size.
Static Field is actually more damaging than Fire Wall in first few shots, but later wanes in strength. When that happens, switch to Nova.
The Sorceress has no minion to summon, unlike most other classes who usually possess at least one type of summon. As such, her only cannon fodder is her hireling, buying her only a short time.
Never, ever, ever confuse the keys between Fire Wall and Teleport. If she uses Fire Wall instead of Teleport, she may give away enough time for Duriel to butcher her. If she actually makes the rather comical mistake of using Teleport instead of Fire Wall, Duriel will see this as indicating the Sorceress having suddenly been kicked out of her mind in fright of his huge stature and amuse himself by hacking at her with his trademark wicked grin on his face. Therefore, never make the mistake of confusing between the two spells.
The lightning way is far safer since it takes only very little time to severely hurt Duriel, so a levelled Mercenary should buy enough.