Against d4 I play the King's Indian and Gruenfeld. But against e4 I only play the Najdorf atm, I want another defence as a surprise option that will fit my style i.e. aggressive + counter-attacking and the ability to put white away quickly if he doesn't know his theory.

I have looked at the Marshall and it looks very appealing to me, but I'm concerned that it might be a waste of time because White can avoid it in so many ways i.e. Open Spanish games + Anti-Marshalls, so I may only get to play a Marshall game 1 in 4 times.

If there's any KID/Gruenfeld players out there who can recommend some e4 openings for me to look at that would be greatly appreciated.

Cheers,

NextLvL

You won't get a Marshall anywhere near 1 in 4 tries.  More like twice a year, if my experience was any indication.

Consider the Schliemann.

ruy lopez

No. Just... No.

What! White can even divert before you get a Ruy Lopez.

French can be a nightmare for White especially if he doesn't know the stuff. The typical game is very similar with KID in that players must pay attention to the timing/strategy in handling each Queenside wing and Kingside wing (except that in the KID Black gets its share in the Kingside).

And French is as faulty as KID at high level, so why not?

Play the modern (1... g6). I'm not going to say it plays like a KID or Grunfeld, but it certainly gives you what you're asking for.