Passion Deluxe

Passion Deluxe, also known as Embrace of the Snake Princess, is the Sacred Gear wielded by Tatsuki Kawaguchi, the bishop of Alice Berith's peerage in DxD: ExTrA. A low-tier Sacred Gear, it allows the user to become immune to anything as long as it consumes deadly quantities of what they want to be immune to.

Summary
During their confront, Tatsuki says to Hiroyuki that, unlike fellow evil piece member Shinra Saotome, she does not possess a holy sword, but instead a Sacred Gear called Passion Deluxe. She complains that, since Hiroyuki is not a certain type of foe, she won't be able to shown her sacred Gear for him, explaining its properties before sheepishly drawing her knife against him.

Appearance
Passion Deluxe manifests itself on the own user, appearing as a light bluish glow running through all of the user's body like veins and capilars.

Abilities
A support-type Sacred Gear said to be the "Ultimate antidote", Passion Deluxe has the ability to make the user immune to almost anything. By suffering enormous damage of a certain type of attack, tatsuki claiming that the level for it must be deadly to Passion Deluxe to properly work, the user can become immune to practically anything. I.e. If Tatsuki injects a deadly amount of poison into her system at once and survive, she becomes immune to it, no matter the dose she might receive afterwards.

That is not limited to poison and venom, as Tatsuki shown to be able to withstand light attacks from angels and fallen angels, which would normally kill low-class devils such as herself, since her body became "immune" to it, and she also survives a rampage from a mad Baraqiel, becoming "immune" to his lightning mid-fight, and balancing their match a little. Tatsuki also becomes "immune" to abstract concepts, such as madness, after being tortured to nigh-death.

Weaknesses
According to Tatsuki herself, she receives the "worst" Sacred Gear, as it'll only work if the user receives said punishment to a certain dose to nigh-death, otherwise it won't work. Basically, Satsuki needs to both receive a deadly dose of what she wants to become immune to and not die in the process, becoming a specially problematic Sacred Gear since even small scratches of holy objects can kill them. Because of that, she becomes the main tank of her peerage, risking her own life in order to both protect her allies and develop immunity to anything.

Tatsuki says that she also needs to develop new immunities for different types of Sacred objects and swords, as she developed immunity against Shinra's sword, yet a fragment of Excalibur did harm her during her fight.

Balance Breaker: Royal Serpent Climax
Royal Serpent Climax, also known as Erratic Love of the Serpent Queen, is Passion Deluxe's balance Breaker. From her shadow, Tatsuki creates a massive translucid purplish dome that can engulf an area around 10m cubic, that follows Tatsuki as its center. Once someone is inside Royal Serpent Climax, all of its stats of immunity will dangerously decrease, reaching nigh-death levels. For example, if someone inside the Dome lose a small quantity of blood, their bodies will interprete it as massive bloodloss, and the victim will die from possible anaemia. It can also work reversely, as when Hiroyuki swallow a small drop of water and almost drowned in it, and when an angel took a deep breath and died from oxygen poisoning. The only way to escape is staying away and avoid contact with the dome.

Tatsuki herself, unsurprisingly, is not immune to Royal Serpent Climax.

Trivia

 * This ability is heavily based on The Deathdealer from the Bleach series.
 * According to Alice, she and her peerage almost died when they confronted Tatsuki, only winning because the latter suffered from bloodloss during their fight.
 * Tatsuki also notes that Passion deluxe also works with flavours, since she no longer can taste spicy food after a super-spicy curry.