Comparing all games my most beloved fighter might be Jin Kisaragi from BlazBlue Calamity TriggerBy "your most beloved fighter" I'm pretty sure the intended meaning is "your most beloved fighting game", considering "a fighter" is very often used as a shortcut for "a fighting game".
If I struggled to the end of my determination, to the end of my way of life with my followers, if the result is ruin, then this ruin is inevitable. Grieve. Shed tears. But you cannot regret.