Backstory time:
After getting caught in the crossfire of the final battle between a magical girl team and their villain and surviving Yosemite ended up getting powers.
They found out they were rather strong but with the big villain defeated there wasn't a need for them or any magical people. Not wanting their new found powers going to waste, they secretly started causing disasters so that they could show up and save everyone and look like a hero.
However they started finding it way more fun to cause these disasters than it was to save people so they eventually started just doing the disasters because they could.
So the goddesses/the ones who created the Aphelions and therefore the magical girls sent Aphelions for a new group of magical girls to stop Yosemite, this being Cosmellas Knights
