So, Tahm just dropped a hint of what's to come in the Bilgewater Event

As some of you may know, Master Chef Tahm Kench is THE Roastmaster of League of Legends. The catfish boasts a hearty 46 taunts to multiple champions. He has 2 for himself.

Enemy: "Your attempt to be monstrous is as successful as your dictatorship." Ally: "You're a man with troubles. I have solutions."

I am going to make the assumption that GP is going to act like he's Blackbeard to make sure he brings all of Bilgewater together under his flag. And the fact that Tahm said your "attempt to be monstrous" suggests that any cruelty that Gangplank shows or feigns is just an act and that he isn't the most ruthless of people.