Unmissable story achievement - this is
STAGE 5My 'non-spoiler' guide would be: Air attack, dodge, dodge, air attack; repeat.
(just to clarify, by air attack I mean the jumping, honing attack)
For those still struggling:
*** Spoiler - click to reveal *** 1) 3 rings of rings spawn, but maybe don't rush to pick them up as enemies spawn inside them not long after. You have to kill these to progress, so air attack them then pick up the rings.
2) Zavok will start a laser attack from his wasp-mech. This is pretty simple to dodge as you can just run around the edge of the arena. You can also go underneath him/ the laser - just don't go near the end of the beam. This only lasts about 3 seconds.
3) Around 12 enemies surround, and then dive-bomb into you. This is again pretty easy to dodge if you just keep moving, as they attack where you just were.
4) Zavok will move above the platform you are on for a slam attack. You can easily see where he is, and when he is readying up to attack, by his shadow. Again, he is slow, and so it's easy to move away from him.
The slam attack make you jump in the air, to which the air attack icon appears. You can just spam A to get 3 hits on him (the first 2 he actually reflects, then it's the third that hits).
Repeat 1-4.
After this, the stage gets smaller. Step 1 (rings) happens, but at the same time he will charge across the stage with his wasp stinger a couple of times, then he'll move onto Step 4 (slam) as normal. You don't have to kill all the minions this time, but it helps, and he may even kill a few for you with his attacks.
Repeat this, and then hitting him with the air attacks the fourth time should be the final blow.