After entering the warzone, Rocky went to see Karina, and she immediately requested to withdraw from the Allied Forces. Marshal Mannstein naturally understood that Rocky was trying to poach talent from the Alliance, but he didn't care about it.
The Alliance did indeed value Karina, but no matter how much they valued her, she was still only a City Lord who had upgraded Sky City to a medium-sized city just last year. Losing her wouldn't affect the Alliance much. Thus, Mannstein decided to treat it as doing Rocky a favor and intended to approve Karina's departure with a simple stroke of the pen.