Yes, this for me! Was stuck for a while but he went down to Lydia's sword last night after he followed me into the chamber leading to his cave. I think it may be slightly glitched, in that he wasn't casting at her at that point. Anyway in the 20 previous attempts he was one-shotting me with Lightning

Edit:Lvl 12 Dunmer destro/archer in robes

Elder Dragon. It didn't help that I was fighting two at the same time.

The centurion. not sure if this classified as bug / cheat / exploit, but he's soooo easy to kill. I can kill him without using any perks.

A giant and 2 mammoths at lvl 21; flawless dwarf armor, a lot of kiting, and no alchemy. Though I did have one +20% destro pot.

Would you say armor cap is a must to go toe to toe, and taking blows with a giant? I could take two hits. But I didn't have a shield to test.

So far, it's an in-between of Wisp mothers (they tear me up for some reason) and the Uderfrykte

I think its the Draugr Overlord that one shots you with his ebony bow full of poisoned arrows? That sure was an interesting fight on my level 20 summoner (didn't have Dremora Lord yet). Krosis was a nasty surprise too as he was the first Dragon Priest I fought and REALLY wasn't expecting it.

These days my two Dremora Lords can handle pretty much anything if needed although I usually only have one out while having a Dead Thrall summoned.

I've never had any problems with Wispmothers, Draugrs of any kind, or Trolls. I play a tank warrior though, with a full set of heavy armor and a two-handed axe, or else a sword-and-shield.

The only things I have consistent problems with are the Dragon Priests. Morokei specifically gave me a hell of a problem when I first fought him. I had to get really creative with that fight. It was fun.

I play on Master difficulty, for the record.

As a pure mage I can win pretty much any 1vs1 without taking any damage at all. Problems arise when I have to face multiple foes and end up getting swarmed.

Uh that is called being good, sir. You know how to play... Nothing wrong with that. And I'm being serious.

This may sound ridiculous, but i have to answer chaurus.
Yep, i'm on level 12 and can deal with quite may monsters, even for instance trolls and those disgusting falmers.

But in a cave where the falmers live, there are also chauruses and it is rellly stupid, but those giant insects kill me in a couple of seconds.
I couldn't do more than flee after killing a couple of falmers. I just can't deal with the chauruses.
Btw, is there some trick to survive the chauruses?

I agree with the chaurus, nasty little things. The first one I saw I figured, "Bah, little insect you're dead.". But then, I was dead...

Those dragon priests. They're tough.

Chaurus are bastards. In Blackreach earlier, I was fighting a Dwarvern Centurion, and nailed it no problems, only to be nibbled to death by one of the little buggers.

to day i was was "visiting" morokai, this mana/life absorbing human with unbelievable high hp. i needed a mix of over 20 casts to kill him! i would prefer 2 dragons at the same time before i choose one of those masked-idiots ^^

i dont know about you guys but i walked into a bear cave with 5 cave bears... they yogied me to death twice and took my picnic basket.

Everything thing is 3 hits from my bow or less (dragon priests, deathlords and no name dragons are 3 shots), but before I was epic, I had so much trouble with hagravens,Ice trolls and Giants.

My toughest encounter to date was facing a blood dragon + ancient dragon in 90% open space

Morokei for sure. I was about lvl 17 or so mage. Yikes. The only time i had to adjust the difficulty down from Adept.

Since then, my toughest fight was against a Thalmor Hit Squad. The Justicar had a Staff of Lightning Bolts. Yikes... He stayed right in my face. I back peddled into some giants and mammoths, and lost Farkas brother (cant remember his name) couldn't even find his body. think he got kicked by a giant.

Since that fight i now own some enchanted items to resist shock and resist magic, so hopefully that pesky Justicar won't own me again.

I've only ever fought 1 dragon priest, and I forget which one it was (not Krosis) but he would've been the most difficult for me had I not pulled off 2 30x sneak attacks on him.

Beyond that, I havnt really faced many things that put up a very strong challenge. When I was a lower level 8-10 I could not do anything against the ice troll on the way to high hrothgar. Until of course I got the last word of unrelenting force and blasted him off the side of the mountain

Rahgot is the worst I have faced. It took me a few goes and I got him by just running at him and hitting. Just getting him down as quickly as possible. Unfortunately, after that was over I still had to deal with 4 Draugr Wights and I had already lost a lot of health and used up my potions (the dungeon leading up to this is pretty hard). Luckily I had dawnstar handy and they get scared off after one of them explodes, then you can just run them down.

I ran into Morokei quite early on as well - I got sent on a quest to his dungeon to retrieve something to get the Dawnstar weapon - man that was a very long and difficult fight - I think the biggest difficulty was the lightning draining my mana and everytime I got close to whack a few hits in he cast a lightning wall at my feet (he was right against a corner and didn't move) so I had to back off and hide, heal and repeat

Hmm, lets see... What I hate about Dragon Priests is that they keep turning my atronachs against me. My strategy mostly consists of hiding away from combat, summoning an antranach, and re-summoning before they can be turned against me. I once got stuck on a save where a bear was attacking me from the side of a mountain three hitting me. Thankfully, my werewolf form was able to take care of him easily.(Wish the same could be said for Wisp Mothers, I'm just staying away from them for now). Right now my biggest pain in the rear is the falmer. They keep ganging up on me, and my magic just doesn't slow them down. I'm hoping once I get the perk that makes dual destruction spells stagger opponents, they might become easier. Perhaps I should just go werewolf on them until then.

i was completing a side quest about finding out who's responsible for some murders in some light house.

to make a long story short, you have to fight loads of chocurus, while finishing off by killing a giant one. it was like a nightmare, it killed me with one shot with its venom...
so yes, i must say it was the toughest monster ive vs yet. :/

Well my first companion quest, my char was lvl 10 dual wilding swords/light armor, sent me to a falmer cave, that had falmers! chaurus, and at the end a Falmer Gloomlurker, that could kill me with 2 power attacks and a Dwarven centurion, fortunatly I only had to kill the gloomlurker, so I kited him away from the dwarven centurion, still it was a fight that took me almost to the exit of the cave.

For me Krosis just fell of a cliff and died.