Peter is a by the books no nonesense kind of person, as demonstrated when he had several humans executed for being labelled as traitors. He is also someone who is willing to scarfice others for the sake of keeping the promise.
He hates his brother's Goldy Pond base. chapter 73 page 1-5
The two of them originally had a good brotherly-bond. Peter even agreed with James his way of thinking for a while because he thought that it was better. This seemed to be a facade when Peter revealed that he was just pretending to agree with James' plans. Peter even went as far to take James his title of the 35th head of the family and claim it himself. He then ordered his underlings and the rest of his clans to kill his own brother, implying the hostility between the two.
Bayon hates Peter when he found out about the tunnels in Goldy Pond. chapter 83 page 18
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