I acknowledge the fact that Taro is just a low-budget Zabuza and that he was just some arc we made up to let these two get out on the road together. I'll let you know if I come up with anything related to the experiments, but I don't have plans to give Taro a greater motive than money and possibly revenge on the Leaf for something that happened in the previous war. 

Botan learning spirit gun is almost as juicy as the old Kurama and Botan discussion we had >:3 how do you keep up with so many roleplays?