LUO YAN'S steps faltered because of the sudden lack of light. The whole coliseum was just filled with darkness. Remembering the crystal ball that Luo Jin took out earlier, it was obvious that this sudden darkness was related to that.
He turned his gaze back to his brother. Although the whole place didn't have any light, as an elf, he could still see a bit in this darkness. Not completely, but enough to let him move around with no problem. Most races in the game, except for humans, had some kind of night vision.
This darkness wouldn't hinder him that much. Surely, Luo Jin also knew that. But his brother wouldn't do this move without any reason. He definitely did it because it would be disadvantageous for Luo Yan.