hanging the subject a little: Missing Nin from Sand Village as mid-game antagonist. A bit like Sasori, but pathologically agoraphobic in addition to deserving immortality as a living puppet. Instead of hundreds of puppets, they have a single armor puppet made from several different defeated ninja while using fuinjutsu to make it bigger on the inside and store human-puppets that serve as modular weapons.

By the time they show up, the PCs are decently well known and are being targetted by the missing-nin to be incorporated into their "sanctuary."