It might be hard to believe, but at one time Act V of Diablo 2 had twenty-five special unique monsters on it. After deciding that was a bit too much overkill, five were removed. Even at twenty, this is still about double the number of fights from the average of Acts I-IV. Players always want their money's worth when it comes to extra content. That extra content was delivered in spades for the expansion, taking the form of both thrilling battles and raw pain.
The worst-ranked sub-bosses shouldn't be confused for an Act I elite mob. Blizzard was well aware that players at this stage likely had every piece of gear they could possibly want and every skill point masterfully invested. So they adjusted these fights accordingly, assuming that players believed they would be prepared. This expansion proved to the community that the toughest challenges were still to come.
20 Thresh Socket
Everybody from the rough and tumble barbarian to the nimble and precise Amazon can use additional gear. Thresh Socket has a big chest strapped to his back and makes for an obvious target. Indeed, this was a super unique monster that appears best suited for farming and doesn't pose a real threat.
19 Pindleskin
The druid in Diablo 2 may or may not be worse than the druid in Diablo 4, but even the weakest of druids at this stage in the game knows how to handle a zombie. Pindleskin's fire enchant is really only helpful if he can get a few hits in, but he's just too slow to make that happen.
18 Dac Farren
Much like Pindleskin, Dac Farren's Cold Enchanted bonus only matters if he can connect with his blows. Classes like the druid take time to understand, but Dac Farren will likely not pose a threat regardless of how badly built the given character is.
17 Madawc
As one of three guardians, Madawc is embarrassingly worse than her counterparts. She throws hatchets which deal very little damage, even to lightly armored players. There are games to play to pass the time until Diablo 2: Resurrected comes out. Play those games to bide time instead because this fight will be over for poor Madawc in just a few seconds.
16 Eldritch The Rectifier
Poor Eldritch is probably the most killed monster in the game. He's close to a waypoint and drops great gear, so it's common for parties to kill him on repeat. Plus he's so easy that players who choose their class based on their zodiac sign will be able to easily dispatch him.
15 Snapchip Shatter
So long as the character can do any kind of damage besides cold, Snapchip Shatter doesn't really inspire terror in anyone. There are a few excellent mods for Diablo 2 that can beef this monster up, but as far as the base game goes, he's a one-trick pony.
14 Sharptooth Slayer
The Sharptooth Slayer is fast and that can be deadly when combined with another bonus on Hell difficulty. On the normal settings, he'll get his licks in but he doesn't have the power to his punch to pose a real threat. Maybe his other bonus was part of the game's cut content.
13 Frozenstein
Some super uniques were designed with one and only one character in mind. The ice-spellcaster sorceress will be in a lot of trouble when coming across Frozenstein. Everybody else will have a good chuckle at her expense and then breeze through this battle.
12 Eyeback The Unleashed
Extra Strong and Extra Fast bonuses stack nicely together and so this fight is when the real challenges start to kick in. On the standard difficulty, a little armor and some burst damage can toast him, but higher difficulty settings require careful thought on how to approach him.
11 Bonesaw Breaker
Usually skeletons, even special unique skeletons, are to be laughed at and destroyed. But Bonesaw Breaker and his minions all come with a special charge attack that makes them a ranged and lightly-armored character's supreme annoyance.
10 Colenzo The Annhiliator
Colenzo is one of the sub-bosses encountered in the game's final approach. He originally appeared with a group of unique-looking and buffed shaman units. Then a patch came and while he's still not shabby, his minions have been reduced to the same old one-hit kills as the shaman units from Act I.
9 Talic The Defender
The shield and heavy plate armor will fool rookies into incorrectly guessing how Talic attacks. He's actually a barbarian, even according to his lore, so brace for whirlwind attacks when next to allies and a huge Concentrate blast when standing alone.
8 Shenk The Overseer
One of the nastiest parts about Shenk is that he pops up as the second special unique unit in Act V. So before players have all their new gear yet, Shenk comes along with an absurdly sized army. He isn't too nasty by himself but he actively buffs his minions so long as he is alive.
7 Ventar The Unholy
Ventar the Unholy is a speed demon (literally). He doesn't appear to have anything special aside from the Extra Fast bonus but he's based on a unit that is already quick and hits hard. These base bonuses are amplified for himself and his minions.
6 Bartuc The Bloody
Among Baal's final layers of protection is Bartuc, who comes with a score of minions. He's got a Lightning Enchantment bonus to go with the usual fire attacks on this unit, meaning that he'll be dealing damage from two sources with each swing.
5 Korlic The Protector
Between the three guardians, it's Korlic that outshines his peers. He hits hard with his two-handed axe, but the worst part is that he will use Leap and then follow it up with a Bash. This will outright kill many ranged classes that fail to dodge the combo.
4 Achmel The Cursed
Aside from Lilith, no other special unique in the game gets the Poison Enchanted bonus. Poison damage is not covered nor reduced by most types of magic resistance, meaning that the damage can really add up over time, especially for tanks who haven't had to worry about this damage source until now.
3 Lister The Tormentor
The Spectral Hit bonus is a nasty one as it does magic damage from a random source and comes with an increased chance to hit. Lister gets the benefit of this, but so does his pack, making this one of the hardest fights for those who don't have thick armor and strong resistances.
2 Nihlathak
One might see no bonuses and assume that the gigantic army around him is his only protection. That's only partially true. He actually has several spells, but one of those is a corpse explosion that has a massive radius. As players kill his army, the corpse will detonate, bypassing defenses and also injuring themselves.
1 Baal
The final boss of the game is also the hardest boss in Act V. He has something to counter virtually every build, like a mana burn that automatically takes away 50% of the player's mana supply, tentacles that pop out of the ground and do immense physical damage, and both fire and cold spells. Tack on his deep health pool and players will have to shore up every single flaw to finally see the credits roll.