Ah, the practical kind. I used to study Krav Maga but stopped at E1 both to focus on other things and because I hated teaching. Good luck and hopefully you can only prevent harm to others rather than become involved in a bad situation because of this.
Just got a job offer to teach martial arts in a dangerous part of the city (I live in Mexico, so I'm sure you can imagine). Pros: Pay is amazing, I can teach people over there how to defend themselves, the head instructor will help me attain even more martial knowledge. Cons: High risk of injury and death. I accepted, I hope I made the right choice.
That trope is alive more than ever, not so much elemental Crystal's but gathering magical objects or doing "task" to unlock this oddly specific thing is everywhere, I saw it saw it in the IT 2 remake, avengers and every season of supernatural