Changed the cat's name?

this is Petya

For those who don't know, this is my cat Chyortik, and he has had this name for almost a year. But my brother didn’t like the fact that the cat’s name was Chyortik (from the Russian word “devil”) and he suggested to everyone (me, mom and dad) that our cat’s name would be Petya. Why this particular name? According to my brother, the names of our cats Vasya and Petya sound ordinary, as they do in Soviet cartoons. But - Vasya and Chyortik... are they really brothers?
That’s why our Chyortik has been called Petya since June 15, 2024.