I'm convinced now that choosing an evo weapon outperforms both rondo and the BZ prayer, feel free to disagree and prove me wrong since there have been good runs with them, but in my experience I perform better with an evo.
The best weapon depends on what side of the monster you prefer, I personally prefer being on his ice side and therefore use fire.
For Fire the Leo Flamesword "Shine" is the best choice, for Ice choose either Purge Frostsword "Shine" or Nepa Icecutter "Shine".
In this fight I'd heavily recommend playing long length.
Sigil 1: [ SnS Up 15 | Beam Slash | Length ]
Sigil 2: [ Element 15 | Element 15 | Element 15 ]
Sigil 3: [ Element 15 | Element 15 | Element 15 ] or [ Element 15 | Duration 12 | Wait Time 17 ]
Switch the Fruit to the respective element your playing.
This fight has the same issue as zinogre as in, if he turns around it will stagger you. Here in my opinion its best to not super armor through it often, just play it patient. Sometimes elze just doesn't like giving openings for a beamslash so patience is key in those moments.
The usual way to avoid this attack is a simple super man dive. To time it correctly and not land to far from elze I usually sheathe my weapon while walking toward his tail and then do a superman dive the opposite way as fast as possible.
This Attack will be difficult to dodge at first but the timing is very consistent to learn. The timing of the hitbox of the second claws will depend heavily on where you are standing, rule of thumb would be to rather dodge early than late however. The animation cancel is not at all needed but I still like to do it. For optimal punishment be sure to delay your beamslash a little to connect the first hit of the roundslash.
After the white explosion position yourself somewhere next to his body and use a beamslash aiming for his head. Listen for the icicles dropping and on the third sound you'll have to evade away from his body to be ready for any follow up. If he does the fast tail drag it will be incredibly hard to avoid sometimes, but since that doesn't take your obscurity away its not a run ender if you get hit.
Even though it is pretty straight forward how to avoid this attack I want to let you know that dodging early here will be necessary. Otherwise hitlag will cause you to get hit which will result in a faint.