Potimas: Become a god/leave the planet.
Shiro: Become independent of D and ensure the safety of the Demon Lord, of the homeroom teacher, to some extent the safety of the vampire and oni and to an even lesser extent the safety of the souls in this world.
Demon Lord: Save the live of the Goddess (the planet's angel, a defensive system that is supposed to protect planets from the interference of gods from other worlds) who basically acted as her mother, restore the planet and kill Potimas (her biological father and the person who turned her into a spider creature, as well as the person responsible for the draining of the MA energy and humans driving the dragons into leaving the planet).
Guliguli: The last dragon on the planet. He is in love with the Goddess, and while he would love to save her, he sees it as more important to keep her will intact.
The Pope: As the president under whom MA energy was introduced and exploited and under whom the dragons were driven off of the planet, he wants to kill Potimas and, while he regrets how much they hurt the Goddess and the planet, he prioritizes the continued existence of humans.
The Goddess: Wants to protect the life on the planet, which she sees as her children.
The System: Make everyone miserable, assist in creating new gods, trap the souls on the planet, restore the planet, change the laws of physics and chemistry to the point of basically invalidating science, make it impossible for Potimas to become a god and lastly make it impossible for Potimas to leave the planet.
D: Be an asshole, like it is proper of an evil god, run away from responsibility and have Shiro as a pet.
This results in a war, after Potimas was finally killed, where both sides try to reach the Goddess, and with that the central control of the System, first. If Shiro and the Demon King's side reaches there first, the system will be destroyed, resulting in everyone on the planet (other than the ones from Earth, the Demon King and newborns without skills) dying and their souls being used to safe the Goddess and the planet. If the side of the Pope and humanity reaches there first, the Goddess's soul will be used to restore the planet and the people won't die. Guliguli and the dragon category monsters that are his underlings try to stop Shiro and the Demon King's side in order to protect the life on the planet. The Hero's party, a group of like four of the students, are on the side of humanity, the other students and the teacher are on the Demon King's side.
In the end Shiro finds a third solution that saves only the souls of everyone but results in her becoming D's pet.