Leena

Affection and combat power are quantified, and you move to the next stage at ~100, ~500, ~1000, and ~3000. If you raise your combat power to the maximum, you will be able to fight on equal terms even in Grade 4 tournaments.
Combat power increases significantly with battle experience. Since you won't die, actively participate in the fighting tournaments (if you feel like you're about to die, it's a bug, so please fix it forcefully).
As the user character will be the master, it is desirable that they are skilled in combat.