Heh. It isn’t “like” boss Shago input reads against you - that SOB absolutely input reads against you. You will never catch him with a counter break and you will almost never get a full combo against him. Stick with high damage single hits and just take the inevitable break.
He’s still a computer, so he reacts to certain things in certain ways. You can probably frame trap him with something like blade dash->DP or something.
Guys I’m gonna have a go at it now and stream on twitch if anyone can pull themselves away from Mira for a moment they’re welcome 
https://www.twitch.tv/marcusmark23/
I haven’t beat him either…Lol!
Before you beat your head in, know that Boss Shago is BROKEN and not balanced at all. He is essentially a Mortal Kombat boss, able to do things that no other character in the game can do. That being said there are things you can do to stop him, but those things aren’t normal things you’d do in a match, but rather tactics that you’d use to just ‘game the system’.
There are many YT vids out there of people beating Boss Shago.
I did it! I actually finally did it!
Thank you everyone for the advice.
https://youtu.be/g3NG4EMBs00
Congrats!
What worked for you?
Congrats