I'm looking for a comic where a kid gets in a car accident with his big sister and her boyfriend and ends up in a coma. The kid gets transported to a different land where he has to fight to escape while the sister's boyfriend is trying to kill him. In the end he kills the boyfriend and wakes up in the hospital where he finds out the boyfriend had died only a few minutes before the boy woke up.
This sounds like Tellos. It had a lot of hype going in and I enjoyed it but ended sort of quickly after the coma/metastory reveal. I believe the writer died, so doubtful we'll see more. Some covers showing the cast:
I don't remember if the evil kid/wizard was involved with a sister or not, but it's definitely possible.