Phase 1, 6 hits total
Fang always shoots 2 barrages of missiles and then alternates between laser cubes and trying to ram you. When Fang has the laser cube thingies, he'll fly in the direction you're facing, what I try to do is rev up a Spin Dash when the terrain is higher, if you spaced and timed it well, you can jump over Fang by jumping over the next high point, which lets you simply wait his 3 cubes out.
When he wants to ram into you, make sure you're at the top in the middle of the screen, that makes it easier.
He'll always do the 8 laser cubes after getting 3 hits, use Avatar to clip him through the cubes or Fireball to just fly around him and wait for him to leave a blind spot you can hit, I find Fireball easier so use Avatar first.
After you hit him 3 times, his ram attack is faster, you can use Slow to time the attack better or Special in midair to spit a fireball while he goes down, I find Slow more reliable personally.
If you hit him 6 times, phase 2 starts, but you get all the emerald powers restored. 8 hits total
The Anton attack has you need to go around him and jump into an Anton from under to launch it into him
Between every attack, he should fire nets at you, I try going fast and jumping when they're about to get fired to avoid it when the single reticle is on the bottom, but if it's on top, I prefer staying still to try and double jump right before he fires. It IS possible to mash out the nets but I swear you need luck.
When he fires bombs from his shoulders, attack the green bouncy balls to send them back to him. You can use Slow or Avatar here to help if you want.
After 3 hits, he'll always follow up with an Anton swarm and get more aggressive when firing cork missiles so you need to take note of the nets when he does that attack, otherwise you may run into it when trying to avoid his cork spam, if he stops attacking and you hit a net though, he'll still cancel the net.
If the screen stops scrolling, he's about to nose dive into your platforms, I think he only does this once and when he's taken 7 hits, but stay away from the middle, ideally you'd double jump and use Fireball, his head's vulnerable when this happens though