I really don't know what they did but it just comes across as rigged AI to me. Before I had absolutely no issues with the AI on Hard and Killer. It is just like a crap shoot hoping they don't block, or counter any move you do, and if you do get a hit on them they will break your combo always.Yeah, the AI in arcade mode is really difficult, I was playing on Easy and had some trouble. The guys on the Microsoft Stream last week couldn't beat medium difficulty during the stream.
Before the higher difficulty AI was beatable but challenging and fast, this just seems like a rushed way to amp up the difficulty. The reaction time and guessing the computers do on "Hard" or towards the end of "Normal" in arcade mode is too perfect.
I felt more frustrated and annoyed than challenged, someone I never thought I'd say about this game.