Chances are he sucks ass. He probably can't compete at level 30 and made a smurf to try to own/rage at new players. Just ignore 99% of what people say in game. Find a friend to play with, add people from your games you thought were good and invite them to your games. Play with people you enjoy playing with and the game is much more enjoyable, even if you loose. I have a group of people I used to play with very regularly, several of them were very far below our skill level, but they were fun to play/vent with and so I don't care.
As for Brand, he relies on zoning in order to hit skill shots, he's definitely one of the strongest mids, that said I'm sure Cass can hold the lane against him, especially if she counter zones with her w, I was in that game and you did fine, me less so. I didn't realize off the bat I was going to have to solo with Taric lol, that worked out subpar. I prefer bot lane I think. That said my AD Taric is 6-2 in the last few days haha.