For crossing the boundary, Elena did not need to break it forcefully like most of the derivative concept users had tried. She simple used the concept of space to open a small pathway leading to the outside. At the same time, she also used a specialised barrier to prevent the void from effecting the universe.
Seeing this, Nyxarae was amazed. As she was one of the individuals who had tried very hard and failed in breaking through the boundary of this universe before, she was truly astonished after seeing how easily Elena had accomplished this.
Then Elena invited both of them to go through the path that she had created. Elena was going to be the last one to step outside.
It was unlikely for even most supremes to get the opportunity to go out of the universe like this. So obviously both Nyxarae and Chisato were a bit cautious about this.
