How to write the lore of vampires and werewolves who are a threat to power level 10 characters?
Head vampires and super werewolves. Just up the monster hierarchy and it'll work out.
>>54251349
The official Supernatural Handbook for Mutants and Masterminds 3e has Dracula at Power Level 14. I'm sure there isn't any overt explanation needed for that to be a challenge for players, just make sure you get mileage out of minions.