Sobiesław is a Polish man, due to his parents' situation he had to be with his grandparents most of the time, which he learned a lot about, mostly that's why Gromsko is proud of his nationality as a Polish man, he's prone to correcting people when they say Polish people with their English names, for example 'Marie Curie', he'll instantly correct the person, saying her names is Maria Skłodowska Curie.

Sobiesław is a Polish history nerd.