Jack's personality is relentless, violent, and cruel. He is fiercely loyal to his boss, Kaido, and is willing to do whatever it takes to execute his plans. Jack has a short temper and is quick to resort to violence, often resulting in him causing collateral damage and destruction. He also has a sadistic streak, enjoying the suffering of others. Overall, Jack is a ruthless and feared pirate who will stop at nothing to achieve his goals.