Trolls took as many energy crystals as other monsters, but it was much more effective for them than for others. They didn't have the ice attribute, but Trolls were Primary Chronicle monsters. This was a plus for them in this situation.
They used First Chronicle crystals and got a tremendous amount of energy. Their bodies were filled with it and gradually became stronger.
The Troll Leader was the strongest of them all, and he only had one step left to evolve and become a First Chronicle monster.
When the Troll Leader absorbed energy from several crystals, he reached his peak. At that moment, the monster began to evolve. The first time monsters evolved rather quickly. The whole process lasted only a few minutes. But, during that time, the monster became stronger, and its body underwent significant changes.
Wain watched intently the changes that began to happen to the Troll Leader.