Ninja has a lot of moving parts to keep track of, and they don't naturally flow into each other as there will be times you have to hold onto certain resources because a skill is nearing coming off cooldown or you set up other buffs, such as the suiton buff, for when you need to do a trick attack 20 seconds later.

Once you get the flow of it all, it can be a very fun job, but it does take a lot of practice to get to learn how to play.

Also don't listen to the comment above me. I explain it in another thread, but they are wrong about using raiton to disengage and maintain the GCD rolling. It's never done at no loss to total damage.