I did Azdaja as SMN/RDM (had TH+1 belt though). Drop rate even with just TH1 was 75% of the time I got 2 horns, 25% of the time 1 horn. I used /RDM to build Azure, Sneak is also helpful to avoid skeleton aggro, and extra Fast Cast is nice to have too.
What I did was build Azure to 128, Amber to max (the chest), kept Ruby 0. Used all offensive atmas (Apocalypse, Razed Ruins, and the last one was the one that increased Crit Rate further, forgot the name but it also gives AGI too). You can use any atmas but at least make sure you have Razed Ruin equipped (this will greatly boost Predator Claw damage) and with at least Razed Ruin Atma, you should be able to get Azdaja down with one astral conduit.
Used Garuda and just used Astral Conduit Predator Claw until it went down (one Astral Conduit should be able to take it down). You also randomly get Revitalizers. This was back when I had only 113 gear (mostly just skirmish) and a few 109 AF pieces (AF109 boots, AF109 head, and AF109 body for BP damage). Even with Sparks gear, you can easily farm this.
You can easily get blue chests that refresh all your cooldowns, HP, MP (so you can refresh Astral Conduit) even with Azure at only 128 (don't build Azure too high though, 128 should be enough to keep you up on timers and refresh while giving you lots of gold chests). If you do start running out of time due to unlucky streaks, of course feel free to build Azure in emergency cases.
Of course even without Astral Conduit, it would only take 3-4 mins or so to take down Azdaja (be careful of getting hit by AoE though, the AoE is huge).
I'd farm for gold chests and the NM (after it respawns) in between pops. Sometimes the Azdaja would release a gold chest with the key item in it (which meant 2 pops in a row). I got 75 horns in just under 8 or so hours of farming.
I'd say SMN is one of the best NM farming jobs for Abyssea (they can easily build Azure and Amber lights; avatars are really strong with Atmas, and being able to refresh Astral Conduit at almost any time means every NM goes down in 30 seconds or less; finally against NMs or mobs that spam death or some move that wipes out pets easily, SMN can easily just resummon over and over without too much worry). That and having your avatar auto-attack anything that aggros is really convenient.
If you don't have Garland of Bliss, use a Dagger and use Aeolian Edge (use Atmas that increase magic attack bonus, wind damage if you are using Aeolian Edge, etc) to build Amber. Once you have lights built up, switch to at least Razed Ruins (crit percent + crit damage), and any two atma you want (I used another atma that increased crit percent and used atma of apoc for triple attack rate).
Also for MP, you generally can easily get it back with Spirit Taker or just blue chests, so you don't really need to equip any MP refreshing Atmas (even if you don't have avatar perp cost gear).
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