Since we are getting Kabuto [Halloween] for free this week, it would be good to mention what his new debuff does :

Death Possession
Enemy units who deal damage to Kabuto or his Undead soul puppets will suffer from Death possession.
Unit's under this status will lose their life when using Mystery skill based on Ninjutsu and Chakra cost. This status cannot be cleansed and will reach ninjas with Immunity to debuffs and last for 2 rounds.