Payback
The Old man looked at Sam without blinking. His face is filled with pain, and he is sweating.
His energy is being drained every second and his wound continuously bleeding is not helping either.
Sam has brainstormed a lot for this to succeed.
He carefully planned step by step. Even though, it didn't take long but that doesn't mean his effort is less.
For the plan to succeed, he used the shadow mice to the maximum of their ability.
First step is to confuse everyone in the room and create a fear of unknown. He has to make sure that shadow mice clearly followed his orders to teeth without any hiccups.
And they did.
Second step is that he has to create a thought that his attacks have a pattern. That is why, the old man didn't react immediately when he sneaked up on his back.
Sam only attacked his subordinates one by one in order to create an imaginary pattern which they thought he is following.