Even though base SDXL can generate Jason, i've trained this to capture his looks from part IV, Freddy vs. Jason and the 2009 reboot.

Also, part IV has an unmasked version which is triggered with jasonunmasked. I've tried different captions like "jasonvoorhees wearing a mask" for masked and "jasonvoorhees unmased" for version without mask, but the mask would always blend into his head so this was the only solution that worked. Sometimes you need to add jasonvoorhees to negative when trying to generate the unmasked version.