[Rorkimaru]

At least he (usually) expresses his anger in the diary room rather than getting properly irate in the house. The DR is a place to vent and regardless of his purpose in the house he is human and will feel what goes on. He also seems to be relatively fine with personal attacks on himself but very defensive of his friends, especially the friends he doesn't think can take the abuse. He's upset because the people he cares about get attacked, often because of their association with Mark, and he can't defend them. The only way to protect them would be to isolate himself from those he cares about and hope the rest of the house forget.