Apart from normal skills, Blood Maidens can learn new skills through Blood Transfusion.
Blood Packs can be harvested through the Blood Farm or found while exploring dungeons.
They can only be used once appraised by an expert at the campground.

• Blood Packs which have not been appraised yet can be obtained after battle.
• Take unappraised Blood Packs to the Research Facility!

Using more blood heightens the effects of a Blood Pack.
Transfusing appraised Blood Packs unlocks new abilities in the Blood Maiden of your choosing.