So surely there must be some information on the amount of monsters you've killed and what type they were?
This could lead to some great titles, such as "Charrbane" or "Scourge of the Aatxe".
Make them limitless so they don't count towards KoaBD, but it would be fun to have a title that let everyone know your bloody-minded, psychopathic desire to wipe all Rain Beetles off of the face of the planet

Hell, if not titles, then some sort of summary page listing each monster type and how many of them you've killed, something that a few single player RPGs have done in the past

In fact, expanding on that last idea, some sort of in-game bestiary would be VERY cool; something that only filled with entries as and when you encountered the monsters, with special entries for bosses

Some of the monsters have fantastic character, and knowing more about them would add a lot of flavour to the game.