Senkuu is a straight-forward, confident, and highly logical individual who can come off as arrogant. Even so, his borderline-overconfidence does not cloud his judgment, as he is often backed up by his superior and vast knowledge of science. Senkuu never belittles those who are less knowledgeable than him. Rather, he encourages and inspires everyone around him to do better. Because of his charisma and caring nature, people tend to gather around him, both allies and supporters alike. However, he can act over-the-top at times when he is excited over a creation or at the discovery of something new. (Source: Dr. Stone Wiki)

Katsuki is a very aggressive person and bullies Izuku Midoriya, who he also treats in some ways as a rival. He has a superiority complex and wants to be first, to be the best at everything. He doesn't like when people look down on him, as if they were superior to him, and gets mad easily. He is extremely arrogant, but also very smart and capable. He also thinks of people such as Izuku Midoriya as an obstacle on his path to becoming the greatest hero. (Source: Boku no Hero Academia Wikia)