What? A new skill? Where did you get that information? Of course, it has to be Neinheart. Seriously, he's the worst. You're definitely not at that level where you can master the skill, and yet he's giving you false hopes by divulging in something like this. It's way too dangerous for you.
1) I still want to learn the skill.
2) If you say it's too dangerous, then...

...If you really want the skill, then I can tell you there is a way, but you must prove it to me that you can handle it. Otherwise, what's the point. Besides, this test might be life-threatening as well. Do you still want to do it?

Wait, you didn't have to give up that quickly.

You know there's [map 130020000] at the end of Training Forest, right? Go to the 3rd Drill Hall, take the test, and if you can pass it, bring back with you. Then, and only then, will I teach you the new skill.

Are you scared already? You can give up if you want, but I will call you a quitter from here on out.

You managed to bring back with you. Hmm... that's much better than I expected. Okay, you are now ready to take on the new skill.

I have just taught you a new skill for the Night Walkers, Triple Throw. Please use this to keep justice in this world.

Were you not able to acquire yet? Go to [map 130020000] and enter the 3rd Drill Hall, where you'll take a test. If you pass it, you'll get it. Remember, you have to PASS it.