It would probably take a level 100 player with a melee character. Shalltear was already quite a strong melee fighter, but in the end I reckon these former NPCs (or the people of the land to borrow the term from another series) are in a certain sense more straight-forward and pure characters than players, especially since the original game didn't even allow to reach level 100 following only a single path. Ains is also a combination of a bunch of magic related classes. I'm not sure of NPCs, not to mention the random humans populating this new world, are such or if Shalltear is simply a pure vampire class 100%.
In short, a level 100 melee player would still be a versatile character no matter what.