Danzo wouldn't be working with pein if he killed the messenger frog. Wouldn't make sense, Danzo probably hopes most the town plus the 5th is destroyed so he can take over.
I want to say somehow pa and ma frogs know when one of their own is killed so they will tell naruto to go back.
An wasn't danzo one of the people in the picture they showed of who wanted the uchihaha clan destroyed. So isn't sasukes original targets danzo and the two counselors before he decided he wants to destroy the whole village?
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