Double Entendre.

Legion-1 was beside the lake. He was more or less at the center of the encampment. They saw him take off towards the closest part of the dome blocking his way. So all of their attention was rightfully focused on him when Legion-Unity appeared. It didn't help that Legion- Unity appeared at the opposite end of the barricade.

Legion-Unity appeared right in front of an Origin god with his mouth wide open. He looked like a world beast, but what came out of his mouth was nothing related to world beasts. 

A torrent of charged white liquid poured out of his opened jaws. The liquid plasma exploded immediately after it came in contact with the world. It formed an exploding horizontal white pillar that struck the defensive ring in front of him and the Origin god behind it.