Sounds to me you're looking for a V-shaped in sound signature.
I'd suggest a Beyerdynamic DT990 or Hifiman HE-400, but it would be over budget for you.

So the next best thing inline would be the DT770 Pro from Beyerdynamic. Now, to get the DT770 Pro may actually be quite expensive. Instead, look for the Kingston HyperX Cloud which is basically a modified DT770Pro with a mic jack. Price is around RM400+.

Otherwise, if you're looking for an open headphone with prominent bass, the AKG K612 Pro and Philips Fidelio X1 is the route to go.

Wah, your budget big you should go for other audio brands edi, don't need look at Astro

Is a built in microphone important to you or you don't mind having a separate microphone?

Beyerdynamic Custom One Pro + Vmoda Boom Pro Mic. That's all you need.
Will not match the Kave in bass quantity, but WILL (I guarantee you) beat it in quality.

Not by much. The COP is an efficient headphone, heavy amping doesn't benefit it significantly. There can be some improvement, but don't expect day and night difference.

COP over M-50 if you need mic. Obviously a win situation.

Buy separately... But since I don't need a mic, I just use my Senn Amperior/ HD 600 for gaming. Well, that's before I decided to stop gaming.

For music, yes. Many music players has a software-based EQ.
For other things, you can either use the Windows bass/treble controls (assuming you have one, not all sound drivers supports it) or you can download something like Razer Surround to use their pre-EQ settings.

Although honestly, I don't know why you'd need to adjust bass/treble through software when you can already adjust the bass ports on the COP.

You must understand this very important thing, unlike graphics cards or CPUs, there is no such thing as BEST in audio, anyone who told you so is bullsh~ting.

The COP is a very well suited headphone for bass heavy music, this I can say with confidence. But the best in it? Definitely not. There are bassheads who would prefer something even more (as much bass as the likes of a Sony XB700) for dubsteps. Are you that kind of person?

Interms of gaming, I've found the COP to be enjoyable throughout a variety of games. Single player, immersive games with rich stories, yeah the COP provides enough enjoyment without sounding weak or out of place. Similarly,  adjusting the bass ports gave good positional cues in competitive FPS games, although I've found the soundstage quite narrow, but this is only because I'm more of an open-headphones kind of guy.

Then it comes to movies, similar to music, there's just too many genres in movies to say a single headphone would be the best in all of them. No logic.
The COP to me was enjoyable in action movies, but I didn't like it with dramas or animes. This is because the soundstage was just too narrow for me and the heavy dialog is just too fatiguing to my ears.

Yes, certainly.

The COP doesn't feel as engergetic up top though. Clarity, it's there definitely. Instrument seperation is good despite the narrow soundstage.
So yeah the COP is a indeed a good headphone for you, since the mic is important too.

The M50 is a brighter sounding headphone than the COP, the mids are also more prominent. So in that sense of "clarity" (a very vague term), yes the M50 is better than the COP. The COP however does beat the M50 in the bottom end.