One aspect to consider in Charles Xavier x OC fanfiction is the unique dynamic it can create. An OC (Original Character) can bring a fresh perspective to the X - Men universe. For example, the OC might have a special power or a different background that challenges Charles Xavier's beliefs or ways of doing things. This can lead to interesting character development for both the OC and Charles Xavier.
A common trope is the 'fish out of water' situation for the OC. They might be a new mutant arriving at Xavier's School for Gifted Youngsters and feeling out of place, which then draws Charles Xavier's attention. This trope allows for a lot of character exploration as the OC adapts to this new world with Charles as their guide.
Another idea is a crossover with the Star Trek universe. The X - Men could find themselves on a Starfleet ship. They might have to deal with the differences in cultures and technologies while also trying to stop Apocalypse from spreading his chaos across the galaxy.
Charles Xavier's fate in the comics is not straightforward. Sometimes he's alive, sometimes he's dead. It all depends on the writer's creative decisions and the direction of the story at that time.
One common theme is the power of connection. Since Charles is a telepath, the fanfictions often explore how he and the reader can connect on a deeper level, whether it's through shared thoughts or emotions. Another theme is acceptance. The reader, who may be an outsider or a new mutant, finds acceptance in Charles and the X - Men. Romance is also a big theme, showing how their relationship might develop in the complex world of mutants.
Gandalf from 'The Lord of the Rings'. His magic and wisdom could add a new dimension to the story. He could help the X - Men in their fight against Apocalypse, perhaps using his magic to counter some of Apocalypse's powers or providing strategic advice.
Well, in the current state of the comics I've followed, Charles Xavier remains deceased. However, comics have a way of bringing characters back or introducing alternate timelines and universes, so there's always a possibility for his return in some form.