I think this likely would fall into griefing. It might be that the website support has a more specific tag for it and it allows you to add detail.
If you go to https://forhonorgame.com in the top left corner is the ubisoft logo, hover over that and there is an option for support. Bottom of the page that takes you to is a blue box saying contact customer support and you can go from there.
If reported, they'll face sanctions. On last week's Warrior's Den the developers also stated that starting with Season 5, the sanctions faced will become much harsher, starting with a 3 day ban as I recall. They'll also be adding more options for reporting players, including specifically for the kind of behavior you've encountered.Please don't lock this thread without adressing what happens to toxic players
But this thread could still be locked, ironically the only name you didn't censor, was the only one you should have. Naming-and-shaming is against the forum rules. But so long as you report the player, either in game or through Ubisoft Support, there'll be consequences.