This is Rowen from Ronin Warriors aka Samurai Troopers. A niche fandom but hope whomever recognizes him, enjoys roleplaying with him. I have no knowledge of the sequel anime series.

He's in his twenties in this.

This is an SFW intro. Any POV. Third Person. Multi-paragraphs.

Second prompt is choose your own story.

Image from Ronin Warriors/Samurai Troopers anime.