I would also add that Poison will probably not be enough to scratch those PI in hell, as most undead are highly resistant to it anyway. You'll need elemental or magic damage. Or break the immunity.
I was thinking more in the lines of Nightmare. I honestly don't plan for Hell as I am confident Adriana won't reach it

. Is a HF merc capable of helping with cold damage added from the aura? All in all, I might stick some sort of dmg together for the occasional unique/ghostly champion.
In terms of progress update: merc has slained Duriel. Adriana helped significantly. The tombs until that were relatively easy. Only trouble, as usual, rose with resurrecting monsters, but luck had it that merc was able to kill monsters faster than they were resurrected. When luck was not on our side Adriana made a run for the boss and won time for merc to gain the edge. Until Duriel some failures dropped, including a studded leather (so I know what jiansonz must have felt

), and some assasin weapons. Only one unique thus far (Steelgoad) in entire Adriana's existence, but lots of sets (the belt from Hsaru dropped again in the false tombs; it had even the same durability as the one I already had). And, of course, lots of failed ones.
Now for the details about the fight. I tried in vain to get a Mechanic Deflecting Bone Shield. Adriana checked Drognan's wares EVERY time she was in town in entire Act II. The rumors of the oftenness of the MBSoD (spread entirely by me

) seem to suffer a solid blow. So she had no choice but to settle for a simple Deflecting which she put on switch along with a wand with Weaken charges. I decided to go on main switch with full Cleglaw's. Belt and boots were Hsaru's. I preferred those boots to some with cold resist (17) and MF (18) because Adriana could get to 85% cold resist anyway (with help from potions of course) and I highly valued FRW, not to mention AR bonus. Rings were two rares with life leech (both, 7% total) and some attack rating (79 total), replenish life (+5), +9 life, +1 max dmg, 10% FCR and insignificant others. For amulet, Adriana kept the MF one (18%). Headgear: circlet of luck (31%) with extra defense (40 total). As armor, the MF breast plate (the merc also kept his). The charms added +42 life (for a total of 331), some cold dmg (1-2), a little poison, about 2 dex, 1 str and unimportant others. The char screen shows 19-99 dmg on the attack, 1275 AR (average chance to hit Duriel 95%!) and a little over 800 defense (with merc's aura on). Blocking was only 30%. I was hoping to reach lvl 29 before Duriel as Adriana was very close. Alas, it did not happen so dex could not be pumped further for higher blocking and some bonuses that were level dependent were a little diminished.
I read in ATMA files that normal Duriel has no resistance to physical, but 20% for each fire and lightning, so I chose, for the merc, a circlet with +7 max dmg over others with +fire dmg (18-44) or +lightning dmg (1-72). The chosen rare circlet also had cold dmg (7-19, heavily resisted by Duriel) and dmg reduced by 1, for a listed merc dmg (with savage lochaber axe) of 54-271 and 830 defense (with aura on).
The fight began by me shift+pumping thawing potions from inventory which, only after I realized, did not reach the merc, but Adriana, so merc started the fight with base cold resist (56). Adriana entered the room holding the wand and quickly casted Weaken and switched to smashing gear. Duriel seemed to prefer the merc so Adriana could poke him unchallenged. The merc was very resilient. I took jiansonz advice and stocked on greater healing pots (Adriana had about 15 of them), so when merc was starting to lose life I was already handing him one. He was never in real danger, although Duriel was focused almost entirely on him. Adriana's health never dropped visibly. She also had all the time she needed to recast the Weaken curse when it expired so we kept Duriel's attacks as minor threats. Quite soon he was slivered and Adriana returned to town to re-equip the MF and, this time, proper distribute thawing potions to merc. Upon return, she stepped aside and let merc finish the job which he promptly did. Drop was failed heraldic shield and brandistock, a rare bone shield (which Adriana kept as it was deflecting and had resists) and, of course, a set ring (it might have also been something else but it was not memorable). So one Angelic ring is found. One more ring, the ring mail and we're set (pun intended

). Adriana would be almost entirely green in boss fights (except for the headgear). (Another good tournament, Green with Envy, I think it was called, which only allowed sets and green socket fillers. We should re-play more of the old tournaments as they were indeed fun. Sets/Uniques worshiper, Gambler's Delight are some others that I think were very nice but there are more. Merc's merc I did not, but would

.)
All in all, a very easy fight on /p8, thanks mainly to the tankability of merc (which, in turn, was mainly due to casted Weaken, I suspect). Duriel probably insisted on merc as, when he was looking at Adriana, he was eventually seeing a wand-wielder

. Duriel also dropped fast mainly due to crushing blow assorted with huge AR. Slows target from the gloves obviously helped. Curiously, the entire fighting gear Adriana used, was found (including the Weaken wand). Not gambled (except for merc's circlet), not bought (ok, the merc weapon was cubed using groceries), so the start-of-game MF focus really paid off.
As people insist on making good progress, I insist on posting tables to acknowledge that

.
Code:
Alive characters:
Forum Name Class Char Name LVL ACT WP Version
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SunsetVista Necro Yredelemnul 47 A1(N) Rogue Enc 1.13
japanzaman Barb Babs 41 A5 Crystalline Psg 1.13
HanShotFirst ***Sorc Two 34 A5 Harrogath
jiansonz Assassin Helena 32 A4 Pandemonium Frt
felixbavaria *Paladin Incompetentus 29 A3 Flayer Jungle 1.13d
epaminondas *Assassin Adriana 28 A3 Kurast Docks 1.11
Dazliare *Barb Vladimir 25 A2 Lost City?
xXxGrimmxXx **Druid Roland ? A1 Black Marsh 1.13d
Southpaw8668 Necro Goulash 14 A1 Black Marsh 1.13
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Dead ones:
Forum Name Class Char Name LVL ACT Place of Deeds Version
------------------------------------------------------------------------------
Southpaw8668 *Paladin Lucious >19 A2 Duriel
xXxGrimmxXx **Assassin Noctyria 9 A1 Cave Lvl 1 1.13d
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Notes:
* = this class has been randomly chosen
** = this class has been somewhat randomly chosen
*** = this character needed a random decision that it would not be random :)