I don't think azdaja is soloable. His melee isn't a problem, I can get spiked flail down to manageable levels, and all. But I can't do anything about his spell casting. Hell, it's a major pain to even position him correctly because of all the blood aggro and bindgas.
Tried to pull him into the nearby tunnel twice the other night. Yuly does fine, but he keeps killing me before I can even get the fight set up. And even if I could, blizzaga II and IV are still hurting yuly.
Maybe if you had his atma, but it doesn't seem like you can get his atma for yourself.
Actually I have solo'd 74/75 horns from Azdaja! I have only died twice in all my attempts due to foolish moves on m part.
The Atmas I use are DG, MC, and RR. I tried using Tiger, Slug, Rabbit, and Dipper. By far the best pet is Bunny rabbit.
Slug: Can easily solo the NM however takes a while, HP Down will not stick, and Atk/Def down cannot be used due to being AOE and surrounding mobs. Kill time +45 mins
Dipper: Horrible at taking magic damage... Takes freaking forever.... sometime pushing close to 60+ mins.
Tiger: Huge disappointment. 60k per stack.... Low Defense, Low HP, NM seems immune to paralyze, Claw cyclone is aoe... Razor Fang is so pitifully weak its not even worth mentioning. Very bad at taking magical damage.... very very very very bad at taking magical damage... nukes will do close to 700-800 even with full -DT and DG active and tiger will almost always take full damage from nukes. You will be spamming the hell out of Reward, and even with max reward -recast I was still dipping into my back up reserves of healing salves and Dawns more often than I would like... its doable but risky.. kill time 33-38 mins.
Bunny: Best pet for the job. decent defense, magic still hurts but no where as severe as loltiger or dipper... Bunny will usually take 400~700 from magical nukes. Foot kick will do 300~700 damage which is way better than the Tiger's razor fang which barely breaks 300. Every now and then you may need to pop a Dawn or Healing Salve especially if you over cure and pet takes a -ga nukes/Flail when DG is not active. I only use Relic Boots when using reward to keep over curing to a limit. Even so you still have to time your rewards just right, I usually hold until pet is below 27%. Kill time 30~35 mins, spam that Foot Kick whenever possible.
/NIN is a must.... 3 shadows at all times, sneak at all times.
By far the hardest part of the fight... 3 Shadows are a MUST! You want to position your pet on the NM's Hind legs or Tail. This will cause him to only use spike flail. You need atleast 3 shadows to protect you from spike flail. Also, as long as the NM does not target you specifically, getting hit with flail will not cause you to lose sneak. If solo do not attempt to pull the NM anywhere.... The NM has too many "FU" spells/enspells... Dispel (dispels everytihing +atmas) Stun, Bind, Gravity, sleepga, endoom, encurse, enanemsia, enparalyze, enbind..... Just don't pull the NM, fight it where it pops. Undead is all around the pop location just be patient. The sneak aggro range for the skeletons are actually pretty small. Make sure the coast is clear and make sure you have a safe pathway to run where you can reapply sneak and shadows after pop. With that said it is extremely helpful to know which way the NM pops facing and exactly where the Hind Legs/Tail will be before you pop. With experience/observation it is possible to pop the NM with your pet already positioned on his hind legs/tail. There are 3 ??? for the NMs, I only use the 2 that are closest to the wall/cave because it's less chance for an aggro. The NM always pops facing down the hill you climb to get to him. you want to position your pet slightly behind the ??? at a slanted angle, this will potion your pet near his hind legs. Do Not use 'stay', you want to be able to quickly reposition your pet if your initial positioning was slightly off after popping the NM, if this is the case you only have ~2 second to get the position right before the NM starts unleashing hell on you. I always aim for positioning my pet on the Hind Left Leg because I find it to be more convenient. Also you want your pet to be relatively close the NM, not right on top of him but close enough that the knock back from spike flail does not push your pet out of range and cause the NM to turn. Like I said, getting the initial positioning down before the actual pop comes with experience and observation, with 40+ kills I have a good sense of where my pet needs to be and even if I screw up I know exactly where to step to get my pet in position.
From the time you pop the NM you have about 5 seconds to get hate on your pet, and get out of -ga range.
If you make a complete mess of the intial pop you can still try to solo with your pet tanking face to face. Personally I have never attempted this method so I have no idea if it is possible. I highly suspect only the slug might able to tank him face to face dues to his magic resistance but this would extend the fight duration.
The Actual Fight
Do not engage the NM. The range on spike flail is ridiculous. Depending on terrain, NM's pos, your pos, and pet's pos, range can be as low as ~20 and as far as 35". If you fight where the NM pops then directly behind the NM is the worst place to stand/idle. Flail will hit you as far out as 35+ and will not even show up in log. Best place to stand/idle seems to be in front of the NM or at a slanted angle facing his Right front leg (assuming your pet is on his Hind Left Leg). Simply wait for him to Flail run just in range and spam Foot Kick, then hurry back out. If you go too close to your pet you will get hit by -ga nukes/enfeebles. Keep in mind if your pet has petry, stun, anemsia it will prevent you from using sic. As mentioned, 3 shadows will protect you from flail should it hit, so make sure you have 3 shadows up at all times. You pretty much need to full time sneak since you will be standing in the midst of skeletons. You can run to cave and reapply sneak safely in side, just keep track of your pet's HP before you find a safe place to put up sneak.
Don't Bother, 99% hance you will get clobbered before you can get dipper on nm and out of range. Not worth the risk. I have been many a times tempted to swap out bunny for dipper at 1%... usually ends with me taking a dirt nap.