Stahlhaut

Stahlhaut (鋼の皮膚, sutaruhātto; German for "Steel Skin") is a powerful defensive technique employed by Quincy that serves as a far more effective tool than Blut. By channeling a small portion of reishi through each pore of the Quincy's human body, each of these miniscule reishi particles generate a force-field that synchronizes with other fields to form a uniform network through the skin of the entire body structure. The result of such an action leads to the Quincy supplementing their skin structure with a nearly impenetrable defense from spiritual attacks. It is likened heavily to an Arrancar's hierro. It provides a defense without allowing a Quincy to leave themselves vulnerable to internal assault by attempting to use their imperfect Blut defense, as a strong enough Stahlhaut can defend against any sort of attack that seeks to vibrate physical force through the body and attack vital organs. For example, against an Ikkotsu, a Quincy using Blut leaves themself suspectable to serious injury and likely death due to their blood flow ceasing movement to provide a defense, allowing Ikkotsu's neijing energy to enter the body of the target and eradicate them from the inside. However, with Stahlhaut, they can provide a defensive force-field that prevents that neijing force from penetrating the skin, meaning it will be unable to cause any damage to the internal organs.

Similar to Blut, Stahlhaut has two different systems in which the technique operates, in regards to how it defends against either hard or soft attacks. Both systems cannot be used at the same time, meaning a Quincy must choose which system is needed for what particular situation.
 * Stahlhaut Macht (鋼の皮膚筋肉, sutaruhātto makku; German for "Muscular Steel Skin"): Against hard techniques, such as physical force or a technique such as Getsuga Tenshō, this system of Stahlhaut is utilized. It causes the reishi flow to move against any force that attempts to penetrate the Quincy's body. With enough of a flow, a Quincy's skin becomes nearly unstoppable against any assault. However, the downside to this technique is that, due to a Quincy's human limitations, they can only saturate this flow of reishi only so far before their own bodies can no longer maintain it and they tear themselves apart. Quincies who train in Stahlhaut slowly work their body to being able to use Stahlhaut through conditioning, a similar practice tool utilized by martial artists. In conjuction with Stahlhaut Macht, a Quincy can attack with immense strength, allowing them to overpower even spiritual beings, such as Shinigami whilst in their Bankai.
 * Stahlhaut Sanft (鋼の皮膚温厚, sutaruhātto sanufuto; German for "Gentle Steel Skin"): Against soft techniques, such as Haien, which do not seek to crush with overwhelming force but instead attempt to "burn through" an opponent, this system is used. The reishi flow does not move against the force but instead the reishi flow within the pores moves parallel to the skin itself. This causes any soft spiritual attack to ideally "slide off" a Quincy's body without ever making real direct contact with the body. It causes the skin of the Quincy to take on slippery properties against soft spiritual techniques, as these aforementioned powers are typically difficult to block against, if possible at all. Similar to Stahlhaut Macht, a Quincy's body must be conditioned in order for its effectiveness to be heightened to meet an enemy's attacks.