One thing I never understood about the so-called 'light and darkness' is that a lot of the good cast are overwhelmingly filled with light, with only a few tiny hints that they have darkness inside (Terra has more dark moves than Riku does in DDD, especially with the different shotlocks and commands exclusive to him, alongside an entire dark-based Command Style) but there hasn't ever been anything akin to someone wielding Darkness as their main force that they keep a tight leash on through determination or having enough friends to back them up. Ofc there's the Organization and the Dark Seekers but they're more consumed by Darkness as opposed to controlling it, if that makes sense.

Ansem kept himself alive through sheer force of rage, but he isn't really a fighter himself. What gives?