Blut Vene — Stahlhaut

Blut Vene — Stahlhaut (静血装金剛貝 (ブルート・ヴェーネ・スタルハウト), Burūto Vēne — Sutaruhauto; German for "Blood Vein — Steel Skin", Japanese for "Stilled Blood Guise — Adamantine Shell") is an advanced Quincy technique and a variation of Blut's offensive version, the Blut Vene.

Description
By allowing a greater flow of reishi to enter the Quincy's blood vessels, it becomes possible to further enhance the defensive capabilities of the original Blut Vene by flooding the muscles and organs of the user's body with reishi and altering their chemical density to an extent, subsequently causing even one's skin to reflect this change by becoming a jet black color. By doing so, the result of such an action leads to the user supplementing their skin structure with a nearly impenetrable defense from an opponent's attacks. It is likened heavily to an Arrancar's. In conjunction with Blut Vene — Stahlhaut, a Quincy can attack with immense strength, allowing them to overpower even spiritual beings, such as whilst in their.

Stahlhaut essentially allows for a Quincy to do what no person can do on their own: build up the strength of their internal organs, among other things. They can even protect themselves against internal assaults. It has been shown that even against an attack such as the Ikkotsu, which operates by transmitting the force of the punch through a medium upon impact, the enhanced muscles and organs (including that of the skin) provide a resistance to this force that makes it almost impossible for the force to be carried through the medium and thus renders the Ikkotsu (and other associated types of strikes) useless. The result of this action also means that the Quincy manages to resist against high levels of heat that would burn away even an Arrancar's hierro, among other conditions that normal humans find themselves vulnerable against (such as poison), providing an even more practical defense against certain Kidō spells, such as the Haien, which heat itself happens to be its most dangerous quality.

Variations
Certain Quincy go so far as to create additional techniques to the original Stahlhaut to further make the technique their own, thus developing unique variations.