I started the quest to go through kolbjorn barrow and decided to study up on ahzidal. I already knew what was waiting for me. The problem I have became apparent after reading he was a fire based dragon priest. I based this file off of a character from a book. I have 640 magicka, 100 health, and 100 stamina. I'm a vampire lord, so the sun weakens me even more and I am weak to fire. Something tells me he can 1 hit me. I will have a follower and an atronach fighting him, but I want to know what is a good weakness to extort. I have the dawnguard add-on, and could try the sunlight spells (I used the pacify spell to get the spells on vampire side) but I am not sure.
All the Priests have magic resistance and ward absorb to defend against magic along with mage armor for physical damage, keep an eye on you Atronach as they can also take command of them. Sun or fire magic should be best (as they should be classed as undead). You could try keeping away from him and being the support for your follower with healing and the Courage type spells apparently the buffs will stack, Teldryn Sero (Dunmer fire resist) or Frea (no level cap duel wield and essential) could be good followers.
Lots (and lots) of resist fire but that is very little heath and stamina i always have two hundred as a minimum for any class/character.
Considering that Ahzidal is undead, you're right when you think fire would be the best course of action. I know you probably know this by now, so this'll just be for those who are about to face him.
You can use fire against him, but it wouldn't make a difference. Ahzidal's mask grants him a resistance against flame-based spells and/or enchantments. Now, since that's the case, you would immediately assume that frost spells would work. No, they don't. The mask gives him fire resistance, but being undead gives him frost resistance as well. (This to new people playing the game.)
I was a vampire then and still am. So, you can imagine a vampire facing a flame-based undead priest would be a bit of a problem. Here's something (I think) I've noticed. I decided to turn into a Vampire Lord to at least parallel the gap between our advantages. I started blasting the Drain Life spell repeatedly and I've noticed two things: 1: He sometimes staggers when hit directly, therefore cancelling his charging of his overkill fire blast. 2: When he doesn't stagger and manages to hit you, you can gain some of your lost health back. All you gotta do, simply blast Drain Life until he goes down whilst moving around.
It's not a one-hundred percent guaranteed success should you try this, but if not doing this, then I guess you can always get up close and personal with him and just keep the pressure on with continuous power attacks. I it worked for me when I did it a few more times.
I defeated him Fairly easily. After a few tries I figured out the trick. Before I enter the room I used the dragon aspect shout and immediately as I enter the room I used the summon durnehviir shout to distract him then used megrunes razor on him which gives a chance to immediately kill and after a while I one hit killed him
It took me several tries to beat him as his fire attacks took half my health (with no fire resistance potions or enchantments or anything like that) I was able to beat him by hiding behind cover and picking away at his health with a bow (dont worry about miners he ressurects they're pretty easy to kill even with low level weapons)
I always got one shot by him however found a solution I used moras grasp which freezes him for length of time immune to damage and can't attack used embrace of shadows to turn Invisible with muffle boots equipped went into the tunnel and used sanguine rose to offer hidden support
The way that I defeat him I do call for valor and I allow Serena and the call for valor to handle him while I handle all the Drager they will take his health down to halfway Start using your shock magic and you can defeat him without ever having to throw your sword