I have noticed some possible bugs associated with Valeros's Tale, but they seem to be in my favor so I haven't complained about them. I have come across the Animalbane Dogslicer as well, but I didn't end up keeping it so it wasn't an issue. The one that I think is a bug is that I have complete access to all of Valeros's special gear when I create a new game with him. I believe I need to unlock all of that first. Anyways, I have been able to use it before unlocking all of the levels. If it is a bug, it won't bother me too much to need to unlock it before being able to use it in the future.