I leveled up to level 5 but my character's stats like atk, def and res won't increase. Am I doing something wrong?
From what I gather, that’s intentional.
That leveling up only raises your HP and WP.
If I read correctly, the other stats will go up (or maybe even go down) during story events.
At least grinding the hp and wp stats will be quite useful in some way
In case you want to mess around a bit in combat