So, human children can be mutated by Lapi usage but does that also happen with grown ups? And everyone can use Lapi but is there a limit to how much the crystal can be used consequently without stop? Does it overheat, discharge then needs time to recharge or wear down the users own energy? By what I read I'm guessing that a Lapi has the same effects no matter who uses them but when you said that master magis could manipulate it, do you mean that instead of a, for example, lightning bolt they can manipulate it to take the shape of an arrow or a lightning sword? If there are multiple lightning Lapis with different effects, if someone masters one of them and learns to manipulate it, does it mean that he can virtuality be able to fabricate all lightning Lapis just from mastering and manipulating one? On a side note can you manipulate a Lapi without actually mastering it? So the magi can't recreate that Lapi 's effect by himself, he needs one to pull it off, but at the same time he has learned to manipulate said Lapi. So if he had a lightning spear Lapi, now he can manipulate it and change it to a lightning sword or lightning bolt. Now that Lapi for him* is a lightning Lapi with universal use, meaning that he can recreate all lightning Lapis from that single one he has. What are the benefits of mastering a Lapi instead of just carrying it and using it besides  the fact that you don't have to carry it on you all the time? Does the casting procedure change? Does it require more of your inner energy to be spent?

And finally, could you mold Lapis in your body? I mean if you molded a fire/water/earth/air on your body and learned to manipulate them all, you practically become the avatar.