As we all know, the new season of BR is “Cubed” with Cubes now roaming the island, spreading corruption where they go. I think that this Season answered one of the biggest unsolved mysteries of STW: Where did the Storm come from?
In BR, Aliens came out of nowhere and they wanted to exterminate the inhabitants of the island. They have probably wiped out or almost wiped out other civilizations. Inside the Mothership was Kevin, lots and lots of Kevin and this is where it starts to connect. There’s not just 1 cube but thousands of them and they were all in the Mothership.
What does this mean? The Alien race sent a Cube to the BR island in Ch1 S5 AND they also sent one to STW. The cube sent by the mothership would have created the storm, engulfing the planet and I also think that the Mist Monsters were the first to come. After the mist monsters came the husks which look like they once were human but the skins could just be souvenirs. If you notice, the Mist Monsters have a purple color, the same color as Kevin, and they are different from the husks.
So Kevin was sent to STW and created the storm which eliminated most of the life. It is also possible that Kevin transformed into the Storm King and then created the storm which seems a bit more plausible because Kevin appears once you kill the SK/MSK
The TLDR here is that the Aliens go from place to place wiping out civilizations using the cubes. One of them was STW which was mostly successful and the other was Br which was not. Another thing to note is that the Storm king items returned to the BR item shop which is interesting considering it’s the start of the month and Fortnitemares is still a few weeks away so that may reveal more information