so many characters can have many different “dere” types. i already did a post (crossposted as well) asking if my character Kanami was a yandere, and so far, the consensus is yes. however, would they also qualify as a tsundere character?

The first side Kanami shows to MC (you!, this is like a game/story idea where MC’s features and gender is determined by you yourself) is hostility.

Kanami seems creepy at first, as they are a cemetery worker. They enjoy teasing other people and are quite cold to you (MC) the first time you see Kanami and interact with them.

Kanami then starts to show a more cheerful side to them before they become obsessed with you. In "side stories", which aren't part of the canon story, their cheerful side remains. They are also known as Mimi in the side stories, but when they get more serious in the main story, they go by Kanami. However, in the main story, they develop an obsession with you and end up kidnapping you due to their fear of abandonment. They will do anything for you just so you stay with them forever, including cooking for you, doing services for you, etc.

In the basement of Kanami's house, Kanami has a "safe haven" where they try to make you as comfortable as you can but isolate you from your friends and family and cause you to go missing. Several people have escaped, but they are determined that you won't.

Maybe a tsundere-yandere blend?

Tsundere is “A stock love interest who is usually harsh, stern, cold or hostile to the person they like, while occasionally letting slip the warm and loving feelings hidden inside due to being shy, nervous, insecure or simply unable to help acting badly in front of the person they like.”

Yandere is "A term for a person who is initially loving and caring to someone they like a lot until their romantic love, admiration and devotion becomes feisty and mentally destructive in nature through either overprotectiveness, violence, brutality or all three combined" and "Yandere characters are mentally unstable, deranged, and use violence or emotional abuse as an outlet for their emotions."