He also has many solo projects outside of X, an example of such is titled "Foreign Sands" with Queen's Robert Taylor.
It always amazes me how he can write a piece of music that can be perfromed at incredibles speeds by X and also could be performed by a full orchestra and sound just as good either way.
He is also a sucessful producer. Through his record label Extasy Records, bands of such caliber as Luna Sea, Glay, and Dir en Grey got their starts.
Yoshiki has a very erratic personality, as seems common wiht extreme talent. He has been known to go into near fatal depression, insane rages, or any other vareity of emotions at any time. This may be atributed to his tragic past and family issues. It is said that Yoshiki, as a boy, discovered his father after the later had committed suicide in the family home. Much of that painful emotion can be heard in X's music I think. I believe songs like "Endless Rain" and "Longing" can hold deeper messages about Yoshiki's past. Though it seems that those times have passed, Yoshiki remains a creative force partly due to his unpredictive nature.