The temperature of the surrounding area dropped very quickly and snow began to fall out from the sky. But Fiona already reacted and increased the power of her flame sword. With that flame switch she was able to protect herself from the snow. But, Fiona underestimates Gloria.
The snowfall has already increased. Even those people who were in the stadium can feel the chillness in the air while they were protected by the barrier. With that you can tell how dangerous the technique was. Also the interesting thing was that she didn't even use her full power. She only uses the power of an intermediate C-grade warrior.
Right now you can say that Gloria was using the full power of an intermediate C-grade warrior. Because of this the power of the snow suddenly increased and even when Fiona wanted to defend herself but she was unable to dodge from that snow.