Actually there are tons of monsters in the worlds folklore, just look at Witcher (book, not the game!) there you can find at least 3 types of vampires and many other monsters. Actually adding different monsters living in the woods and swamps and sometimes attacking people and other factions could be good. And for sure you will be able to get contracts to destroy that monsters. So, my suggestion is to make game not only the sell-swords simulator, but also a monster hunter simulator, all at the background of the conflict. Adding alchemist store and different non-magic potions could also be very good imo.
And about monster, here is my suggestion.
Large monster with his body hidden underground, so only a little part of it is actually seen, and is immobile, but he has a tentacles which move underground and can quickly hide and then come up. Your goal will be to fight those tentacles and destroy his body once you manage to get to it.
Sorry for possible mistakes, English isn’t my native. =)
