Sten is the creator of the rain and the leader of Apollon. He is the central antagonist of The Rain.
Season 1
Season 2
"Avoid Contact"
Sten is disappointed in Kira's failure to apprehend Rasmus Andersen, who holds the secret to immunity from the virus. Apparently, the virus mutated in Rasmus' immune system, leaving them with no control over the virus' spread anymore. Fearing all of their deaths, he urges Rasmus' capture before he can learn to "control it".
"The Truth Hurts"
When Kira had Simone Andersen in her sights, Sten ordered her to kill Simone, but Kira instead refused and called off her guards. This allowed the computer, which was tracked, to fall into their hands and reveal their hidden base to Sten.
"Stay in Control"
Sten sent a holographic message to the base, warning them that Rasmus would kill them all, and ordering them to hand him over. More, he offered to help them extract the capsules from their bodies to free them of the rain virus, if they cooperated, allowing them to leave the infected zone. If they did not cooperate, they would be killed.
"Save Yourself"
When they found the base to be empty, Sten deployed Kira to capture Rasmus herself.
Season 3
He is killed by Rasmus after demanding that Rasmus obey his orders and holding Sarah hostage with the threat of fire. After meeting Sarah, his ardor for creating virulent humans becomes greater, and he wonders what allowed Rasmus to infect Sarah without killing her. Fie realizes that it is because the virus did not meet any resistance in her body because she had no immune system. They decide to test this theory by having Rasmus infect a terminal cancer patient, who later revives.
Sten demands that he is the next to undergo the transformation; however, given that he is a healthy human, he is put on a special cocktail of chemicals to 'prep' him for the infection. As his immune system is being neutralized, Rasmus enters the room. He tells Rasmus that he still has around an hour before he will be ready and that he loves him like a son. Rasmus insists that he will infect him now, and Sten realizes that Sarah has entered the room on the opposite side of the glass. He is too weakened to do anything, laying down on the table as Rasmus kills him.