Tower Princess

I personally unlocked this after level 10 sword level 9 musket. This does take awhile to unlock so going out of your way to kill a few extra kobold is ideal. I tried courting how many i got in a run but i lost track after 30 or so as by that point i was more so just on auto pilot from playing 12 hours in one go. Needless to say do not feel like you have to hit every corner every run finding them as you will be doing plenty of runs regardless if you went the completion.