Karsha received two great rewards from the system when he became a Grandmaster after breaking through with an SSE rating.
The synthesis and Persona abilities were excellent additions to his array of skills. Karsha was strong, especially when compared to his peers. In his current state, he could easily crush any human in the Grandmaster stage without breaking a sweat.
However, there was a limit to his strength. When faced with opponents stages above him, he struggled to get the job done, especially if those opponents were Mutants.
He had already killed a mutant when he was just starting his journey. Although he gained a lot from the battle, it was far from easy, a clear testament to his body's limits.
But that limitation could be overcome. The Persona ability, although it might not seem like much at first, was perhaps the greatest gift Karsha would ever receive.