You can use an octo baloon shield instead of spending a rocket.

You can parry the lasers but since they are continuous, you end up getting hit after the parry and you don’t reflect them back.

The best damage combo once it’s down is to be at 1 heart or less with a molduga jaw knight’s claymore, Evil Spirit armor (Phantom Ganon) or Radiant armor (glow in the dark skeleton luchador), and attack lvl 3 food. This allows you to kill it in 1 cycle. I think the base damage of that sword is 128 displayed, the armor multiplies by 1.8 (cause the jaw is considered a bone) and the attack buff by another 1.5. This assumes the sword has the attack + modifier and is pristine.