The distinguishing feature of Haku-men is his drive move, known as Zanshin. With it, Haku-men is able to literally counter any attack in the game. The tricky part of course, is timing.
There are four Basic Counters, one Distortion Counter, and one Astral Counter.
The four Basic Counters are as follows.
5D - Haku-men's standing counter, this move has a longer startup than his other counters, thus requiring better timing. However, it is active for a longer period of time. The problem with this move, is it's absolute lack of being able to combo anything afterwards.
6D - Haku-men's forward counter, this move catches the opponent, and then shoves them forward. This move causes the opponent to become "dizzied" in a sense, allowing Haku-men to follow up with fairly decent combos. This move has almost no startup, but a short window during which it will catch a move.
2D - Haku-men's crouching counter, this move is much like 6D, it has a very fast start up, but a short window in which to actually counter the attack. 2D will flip the opponent to the other side of Haku-men, causing them to bounce off the floor. 2D doesn't combo as well as 6D, but it's still possible, generally 2D is followed up with 5C > Renka.
j.D - Currently Haku-men's best counter in game, j.D is much like 6D and 2D, fast start up, small window. Haku-men catches the opponent, and launches them into the air. The beauty of j.D is that amount of time the opponent is unable to tech out, which lets Haku-men perform VERY punishing combos. The average combo after j.D does roughly 4500 damage, which is a huge portion of someone's life.
After those, Haku-men has a Distortion Counter.
236236D - Kokujin Yukikaze! - Haku-men's Distortion counter, has almost no start up, is able to catch projectiles and still trigger, catches high and low, and does a large portion of damage. Unfortunately, due to the nature of it, it does not combo well. It's a flashy move, but it doesn't get a lot of love.
And lastly, his Astral Counter
Down Briefly, then Up D - Aku Metsu! - Haku-men's Astral is just like his Distortion counter, same type of window, same basic concept, only it's even flashier, and of course they die if they're caught in it.