Try to Save the World by Level Transfer

Gates appeared all over the world, and humanity was on the verge of extinction due to the monsters that came pouring out of them. Kai, who opened a Gate, had been in a coma for three months after being attacked by the monsters. When he woke, he found not only a mysterious status screen but also a unique ability that allows him to level up other people when he completes missions according to the screen.
Perhaps I can use this skill to save the world ?
If so, I will try to save the world by level transfer !