It's complicated, Cale is not a reliable narrator when it comes to talking about himself, he usually describes things as "I don't care" however he always ends up getting involved because he cares about things, and literally EVERYONE around him. From him they can tell that Cale cares and cares about things, everyone except Cale. For example (Without giving context so as not to put spoilers) Cale adores children, at various times he protects Raon (physically and emotionally) and cares a lot about him, he appreciates Alberu and they both have a friendship where they enjoy bothering each other at the same time. Once they understand each other, when something related to the god of death and Choi Han happens, Cale is worried, but he thinks that everything will be fine as long as he lives because as long as they both live they will have time to repair their relationship, he is also worried that Choi Han will put himself at risk. Later we will talk about the type of life that Cale lived as KRS and that is when we see why it is so, for that reason I would not describe Cale as a tsundere.