So i remember these things about the game, which i played like 15 years ago:

It was on the first xbox; it was kind of a open city/world; you played a male character; you fought mainly with martial arts, (which you could train somewhere in the city too) but i can’t remember if there was other weapons; the last fight was against a dude on top of a skyscraper on a huge balcony.

That’s not much i know, but i hope it will be enough. Thanks in advance!