Bab 382: 382. Finishing a Crystal Ball

"If we do that won't it cause the crystal to break?" Walker thought that the crystal would be under too much pressure having its internal structure changed to store the mana and eventually have the entire shape changed to fit the pure light blade and the pure dark spear skills. 

"You're thinking of it in the wrong way. You have shaped earth before, so that means you know it has the strength to change with enough mana. So it is the same with the crystals. It can change shape and allow the two manas to intertwine and work with each other. If you need a light blade then it can channel the light in to the shape you want the skill to take. If you want a dark spear it can do that as well." Walker was still confused.