I love sasuke's logic:
Clan founder opposed peace, 1st hokage killed him, or so he thought.
Clan was given a great position that made them easy to watch.
Fox attacks, clan known to be able to control it suspected.
Clan turns traitor, plots a coup.
Rogue clan member, under orders, eliminated the trator clan, spares his borther.
Brother later gives up life to protect brother from insane leader.
Leader goes flashback.
Brother, with newpower meant to defend against leader allys with leader to destroy village that brother gave his life to protect.
yeah, makes perfect sense.
Someone hire a hitman, Kishi needs to go.