GD 201 Game Conflict

My game idea might be something to big to make as a class project so I'll save it for the future but I'll make it smaller to see if it works. My game conflict is going to involve a enemy that plans to take over earth and the Hero has to stop him with his apprentice who is his lost lover's sister. After landing on earth after sacrificing himself for his clan the hero (Ahkeem) is damaged but not defeated. The last family he has left is his lover's sister who he promised to take care of and train to become a hero who can protect earth just incase he dies. The villain(Tyken) is also damaged after the fight but plans to strike the hero down for the final time, hoping to end it all. This conflict is going to most likely only involve 4 characters max, to make this smaller. They will defend earth while also learning more about the human life and embracing it as their new home; Even Daya is there but she is reborn as a normal human to protect her from the danger so she has to grow up again but normally.