I am including several classes in Terminal Conflict so you're not stuck having only, lets say, Jutsu, as one of your main skills. With these classes you can have several different abilities. Heres an example of what you could do: a Ninja who gets killed by a Hollow, therefore he dies and is sent to the Soul Society, he may train at the Soul Reaper Academy and become a Soul Reaper, but still has control over his Jutsu and, if he had one, his Demon. It's not the most original thing I could include but It'll do.Also, I'm not going to include any Classes myself. That's your job. Just go and make a reply with all the info about your Class.
Note: Joining a group such as the Akatsuki or SPK would be considered a Class, also.
Note*: I will include information about the statuses of Genius, Permanent Chakra Loss, and Failure.
Genius: Genius are rare but start out with several jutsu and the strongest beginning stats. (Examples of Geniuses: Itachi, Neji, Kakashi)
Permanent Chakra Loss: With this status you'll lose your ability of Ninjutsu and Genjutsu, but your Taijutsu and Speed will grow in strength. You'll also be able to use the Chakra Gates.
Failure: Failures begin with no jutsu, and normally have low stats, but have amazing stamina. Eventually they may learn techniques that others can't.