First off, I want to say I'm sorry your character got ninja nerfed. To take away some of your options when you had little to begin with is unnecessary and kind of a low blow. However, there is some good news I have for you. Some tech you may not be aware of yet that the video guide fails to point out.
Kensei maintains his stance while advancing/sidestepping. Unlike other characters that drop their stance or are locked into a block animation. This enables Kensei to move freely and block at the same time, allowing for an immediate follow up helmsplitter, Swift strike, or GB.
As an example, let's say I'm fighting a legendary raider who decides to throw out an attack aimed to my right side. If I set my guard to the right (or if it's already there) I can dash forward as the attack is about to hit and his attack will still bounce off my guard. Leaving him open for an immediate counter attack.
For the sake of pacing, I'm going to call it a block animation cancel. The timing isn't strict, you can dash anytime before the attack hits or anytime AS the attack hits and you will not go into your "I'm going to block this" lock, but instead dash in your desired direction. However, if you wait too long after the attack hits, you won't be able to dash out of the recoil animation.
Combining this block animation cancel with Kensei's dash attacks and dash GB, gives him counter-attacker qualities while having crazy reach. It's too bad they got rid of his side light into sped up overhead because that combined with the block cancel would give him an amazing kit. Hope this helps, happy stabbing.