NPCs
You'll never be alone in the World of the Dead, because these NPCs will always be here. Some are old, some are young. Some will waste your time, others will teach you techniques that are spoken of in legends. If you know who to talk to, dying may be worth it.
Name: Sekkaku
Description: This old man seems frail, weak, and senile, but in his life he was a ninja with unrivaled power. Want proof? He actually died of old age! He's very impatient with his pupils, and usually refuses to teach, but he is able to teach you ANY technique of the appropriate rank. The drawback? Even if you convince him to teach you a technique, he will ONLY teach you ONE technique. Choose well.
Jutsu to teach: any
Appearence:

Name: Korounin
Description: It'd be pretty easy to believe that this man knows everything. He's a living (Well, not really), walking library. He can tell you of legends long forgotten, tell toy about every jutsu in existance, and his favorite subject, the tailed-demons. However, he will only answer one of your questions every time you die.
Jutsu to teach: He can't teach you any jutsus, but he can give you all the details you need on them
Appearence:

Name: Engan
Description: Engan is mute. Always has been. However, he can be quite useful. In his crystal ball, he can show you what is happening in the world of the living. Though, he can only show you a person or place you've seen before.
Jutsu to teach: none
Appearence:

(More will be added eventually)