Mephiles

Mephiles the Dark returns as a boss in Shadow Generations after being erased from the timeline by Elise back in the 2006 Sonic the Hedgehog game. Mephiles intends to destroy Shadow and restore himself to the timeline, though Shadow doesn't remember Mephiles due to the events of their encounter being erased from history. The annoyed Mephiles notes that this is the second time Shadow doesn't recognize him.

Example of:
The Bus Came Back