Shunsei is shown to be cold-blooded, similarly to his father. While discussing the Chinese team's strategy after their first loss (despite claiming they will win by a clean sweep), Kaioh Kaku said he will fight the other matches, but Shunsei interrupted and said that each person should get a kill and said that by killing all five of them no one would care for them. He is also shown to be arrogant, claiming victory immediately after his father agreed on Shunsei's terms. Like most of the Kaioh he is confident that he is the best and no non Chinese can defeat him.

Spoiler

Unfortunately for him., he underestimated Baki Hanma by a pretty large margin.