Body Double

In embryo you had a twin, however you didn’t like that jerk much so you ate it. Of course they didn’t want to leave you alone even in death. Their spirit lives on within you and fights or works with you for control. Either way you feel like you have very little control over it’s effects on you. In character creation, create two seperate characters with the same race, but differernt classes. At the start of each session you flip a coin to see which character has control of the host body. At level 50 you can choose which character you are. At level 100 you even further gain controll of your switching and can switch characters with 2 hours of good rest.