How can i manage to write a novel which is mostly comprised of super natural battles without getting too repetitive?

Surprisingly this problem isn't all that uncommon and typically is in the form of the following, "I'm writing a book that's inspired by Hunger Games and it's coming off exactly like Hunger Games." Yours is a little different in that battle scenes are coming off as the same, but its still the same problem: You can't get away from a repetitive rut.

The problem happens when you use one source for your inspiration, in your case anime. Because your inspiration is narrow, your ability to create something different is limited. Yes, there are many types of anime out there that spans all different types of stories and conflicts, but for the most part, you have to branch out to other things to be effective writing.

Animes take on a lot of different things for their inspiration, including, but not limited to: current events, mythologies (both East and Western), and history. You should do the same.

Settings are key then; have the battles take place in different locations, from the wide open featureless (a stretch of desert or a field) where the environment plays little or no part to locations where the landscape changes the nature of the battle (a city or mountainous landscape that in effect creates 'corridors' .... a forest where the trees provide cover as well as a vertical component to the fighting [as in archers up trees and such]).

Some settings, of course, are affected by the battle (damaged buildings, trees coming down) while others are not, thereby making the battle change as it progresses (routes obstructed or opened up) ... it depends on where you want to go with your writing, but the fallen also influence the battle (be it that their bleeding corpses create an unsure footing and/or that you have people trying to help the wounded away).

Oh, I don't know. People who like battles never seem to tire of them. Have you ever read a book of the battles of a war? Something like the Civil War, or maybe something about WWII? Each battle had something new and different, and often you can find a thread where Battle A led quite naturally to Battle B, and from there to Battle C and so on until the end of the war. The battles will vary in intensity, in bloodshed, in who wins (of course), and to some extent, who participates. Give your characters different weapons/superpowers, and combine them in different combinations for each battle. Some gaming dice may help if plotting fails you.

Fictionally speaking, you start small and intense, then gradually build up to bigger and bigger and bigger. I think you can drop the intensity between Battle A and Battle B, but then the intensity must start to build again. And fictionally speaking, each battle must set up a confrontation parameter for the next battle. People will want to get to the next battle and see what happens. There should be major loss and major gains in each battle, and corresponding character development.

Make it important. Not just a bunch of random bish-bash.

You have better instincts than a lot of folks by simply realizing this could be a problem I never write battles myself but I would think a key part of a good one would be having very well-developed characters so that the reader is engaged in what is happening to them. I think if you vary the POV of the battles among the different characters that would help too. The same characters fighting the same enemy characters repeatedly would get a bit old.

Create new supernatural beings for the character to fight. Make the character loose some fights, and win some fight but with consequences. And there should always be a main goal, fighting all those demons etc because you want to save the world or something. Use character progression to evade repetition, make it so the character grows in strength and intelligence. Best of luck to you.

You can't.

Sorry but that is why I stopped reading the John Carter series.

They degenerated into one battle after another.

After a wile even good battle scenes get boring.

Study real life battles, and use that. Battle tactics are usually extremely fascinating and can be vastly different from each other depending on the weaponry used, the strength of the individual/army, the geography etc.

On earth, air water and underground.