Filou 7 lb, Tigris 13 lb.
The same role models.
Tigris wants to play. Filou attacks him. If it gets more serious Tigris will always win. Filou also had times when he started to pee in the wrong places because Tigris wouldn't leave him alone.

I had already the feeling that maybe they are competing for your love as well. I had the same impression with my two too. So in the harder times (maybe 2-4 years ago) I did not interact when they fighted (I must admit Filou cried as if Tigris would eat him but I got the impression it was a typical little brother behavior to get Mommy to help) but just saw that after and apart from that Filou could retire where he wanted and to give him as much attention and love as possible when he was alone.

As I have said in another thread at the moment they are closer again and it is much less stress but they still have different times to ask for quality time: In the morning e.g., Filou joins me in the bathroom while Tigris downstairs reads the newspaper with his tummy while my husband reads Tigris

I send the best and positive thoughts. I love Miley so much for what she's been through and I think Ti is a nice and friendly boy in his cat soul and so I hope they'll work it out.