Completing the fictional martial art elements

Hello there. I'm a OPM (One Punch Man) fan and one of the concepts I love about the manga are the martial arts. So when I was thinking about them I realize that they're based of elements but are incompleta because we need fire, earth and Lighting martial arts to complete it. Water Stream Rock Smashing Fist and Whirlwind Iron Cutting Fist represent water and air (Exploding Heart Release Fist represent explosion and not fire). So anyone can give ideas about the 3 remainig martial arts? Please.

I think to create them needs 3 things:

•Name •Stance/guard/position •Special Ability

I already have the special Ability of the earth martial art is that makes yourself body vibrante to increase your attack and defense also with the vibrations you can hit the ground creating earthquakes attacks (inspired información hassoken from One Piece. The master of this martial art will make your body harder than steel and achieving a lot of control over your body. But I don't Have the name and stance. In the stance I was thinking of something like horse stance.

Can anyone give me ideas to make the martial arts? Please.