I made some more progress today and managed to defeat Llengrath on my non-TOI save on the second attempt. The only damage i took that was substantial was from Turisulfus when it was only him left and i decided to try and face-tank him ( bad idea).
I managed to split Turisulfus and Llengrath from the main group using animated weapons, then killed the trash mobs with summoned animated weapons while i moved away with sword and shield in hand in case a xaurip tried to CC me. I split the weapons up so that Gafonercos' acid spit wouldn't hit them all. Once the trash mobs were down killing Gafonercos was easy. He will use tailwhip if you get too close but the animated pike has enough reach that it can tank him safely for a little while while the animated war bow and I shoot him, by this point i switched to the chant that gives bonus accuracy against beasts. Once the pike was killed i moved the animated great sword in to take a few hits and by that point i had 7 charges again. Rinse and repeat.
With only Llengrath and Turisulfus left I drew the dragon's aggro and then summoned weapons to kill Llengrath. To kill Turisulfus i basically summoned weapons and made him chase them while i chased and fired arrows.
Yeah i thought it was going to be much harder than it was. I didn't have shot on the run or marksman, though i did have 95 accuracy with persistence which was enough, i may end up sacrificing superior deflection for marksman or Weapon Focus: Peasant, i also think i left scion of flame in the mix which is useless with the strat i used.
Yeah i've seen that fight. I'm thinking about trying that because it doesn't really hinge on having a great deal of fight RNG as oppose to my current method which relies on me separating Llengrath and Gaf. I think if i use the beast accuracy chant it would be quite potent.