Askin Nakk le Vaar is a member of the Wandenreich's Sternritter with the letter 'D' as well as the Schutzstaffel.
Askin wears the typical Sternritter hooded cloak. He has a thin face, with pronounced cheekbones and full lips. His dark hair is swept back messily, with a single strand dangling in front of his face. His eyebrows are connected to the ends of his eyes by markings. He wears a strange bracer on one arm, seemingly made up of smaller bracers.
Askin is eccentric and sarcastic, quick to mock those around him. He is also quite arrogant, wondering just how intelligent the 12th Division actually are. He often tries to trick his opponents, such as when he attempted to lure Mayuri Kurotsuchi into his range and, by his own admission, hates meticulous things and prefers things to be over and done with instantly. Askin dislikes having to exert too much effort on a particular thing.
Plot - The Thousand Year Blood War ArcAskin Nakk le Vaar interrupts an argument between Jugram Haschwalth and Bazz-B, sarcastically stating that Bazz-B is indeed calm despite preparing to attack Haschwalth. When Bazz-B asks him what he is up to, Askin merely replies that he is saving them, since Yhwach dislikes infighting so much. Askin then warns them that they are being watched, pointing out the Sternritter who is spying on them from afar. Askin tells them to stop fighting and says that it will be nothing but 'poison' for Haschwalth, who he then calls the 'next emperor'. When the Wandenreich invade Soul Society for a second time, Askin appears in the midst of the 12th Division. Explaining to the Shinigami that the Quincies have been storing up their powers for a thousand years in the shadows, Askin says that their plan went off without a hitch. When one of the Shinigami asks him how he got in there, Askin mocks them before reiterating that he has always been there. Mayuri Kurotsuchi then appears from a secret door behind him, confronting Askin about his mocking their intelligence, causing Askin to smirk. Later, Askin decides to retreat from his battle. Askin explains that killing Mayuri will take far too much time for his liking, so he decides to leave. When he notices that Mayuri isn't following him, Askin wonders why. Mayuri deduces that he wants to analyse Askin's reiatsu and that he thinks Askin might be trying to lure him into a trap. Askin is glad he didn't reveal his powers too soon and, as they feel the reiatsu from Captains Toshiro Hitsugaya and Soi Fon, Askin comments that Yhwach had prepared for the Shinigami's resistance. Askin then says that regardless of their efforts, the Shinigami will all soon be dead.
Askin is later seen observing the battle between Kenpach Zaraki and Gremmy Thomeaux.
Watching the battle with binoculars while having a picnic, Askin is impressed by Kenpachi's ability to fight evenly with Gremmy. When PePe Waccabrada arrives and states that Gremmy should be locked up for being a monster, Askin comments that it takes one to know one. PePe replies however by claiming that Askin's one to talk. Askin then prepares to leave, saying he doesn't want to be caught in the middle of their fight when things get rough. He then states after watching someone with the power of imagination perform incredible feats, that he thinks it's a good thing most dreams don't come to fruition. Later, when Gremmy summons a meteorite to crush the Seireitei, Askin states that Gremmy should have been locked away.
When Ichigo Kurosaki arrives on the battlefield and Yhwach prepares to leave for the Royal Palace, Askin questions whether or not he'll be chosen for something.
Askin is next seen arriving in the Royal Palace as a part of Yhwach's Elite Sternritter group, the Schutzstaffel. He is surprised to see he was the only Sternritter promoted from below, causing Gerard Valkyrie to warn him not to be a hindrance to the rest of them. Askin is then surprised to see the Royal Guard trap them in Kirio Hikifune's Cage of Life, before watching Ouetsu Nimaiya arrive on the battlefield. When Gerard is later defeated by Ouetsu Nimaiya in a single strike, Askin can't believe what he is seeing. He looks shocked upon Lille Barro's similar defeat. When Ouetsu takes out Pernida Parnkyjas, Askin appears behind him, only to be slashed. Ouetsu is impressed that Askin was able to read his movements, but Askin comments that he was exposed anyway. Ouetsu then slashes him across the face, defeating him. However, as Ouetsu turns his attention to Yhwach, Askin rises from the ground, licking the blood off of his hand and claiming he always feels close to dying thanks to his power.
Askin then explains his power - D - The Deathdealing. He has the ability to alter the lethal doses of substances. He begins altering the lethal dose of Ouetsu's blood, causing Ouetsu to fall to his knees. Askin rises, stating that he understands how Ouetsu is feeling as he begins to drink his blood. Askin then comments that Ouetsu underestimated him as he thought he was a mere underling. Askin draws his bow, stating that most people often see him that way and it used to bother him, but not any more. Ouetsu slashes his own throat however before disappearing. He reappears behind Askin and tries to slash him, but Askin dodges the attack. Askin wonders what Ouetsu is up to, but Ouetsu comments that if the lethal dose of his blood has been lowered, he just has to lose some blood. Askin reveals that he has Ouetsu trapped though - if Ouetsu lowers the amount of blood in his body necessary to survive the lethal dose, he'll simply die of blood loss. Ouetsu then shouts for Kirinji Tenjiro's help.
A huge wave of water covers Ouetsu and the battlefield. Ouetsu reveals that Kirinji's red water removes blood from the body. Shocked, Askin looks on as Ouetsu dashes past him, cutting him down. Askin realizes he was the one who underestimated Ouetsu, before proclaiming him to be lethal. Blood shoots out of Askin's chest as he collapses to the ground.
Later, when Yhwach activates the Auschwalen, Askin is revived along with the other Elite Sternritter. When Ichigo and his friends arrive and confront Yhwach, Askin arrives with his Vollständig activated. He and the other Elites surround Chad, Ganju and Orihime. After Uryu removes Ichigo and the others from the palace, Askin looks on as Yhwach begins to absorb the power of the Soul King. Later, Askin relaxes with the other Schutzstaffel in the Royal Palace while they wait for Yhwach to finish absorbing the Soul King. Eating grapes, Askin replies to Lille Barro who asks whether they should really just be sitting around. Askin reminds him that if they got anywhere near Yhwach, they'd just be devoured.
When Haschwalth notes that Yhwach has finished absorbing the Soul King, Askin and the others go to find Yhwach in the throne room. As they enter the room, Askin wonders what the black ooze is flowing from Yhwach. When Yhwach turns around and reveals his transformation, Askin, along with the other Elites, is shocked at what he sees. Scared, he tries to back away, only to back into Haschwalth. Haschwalth tells Askin to calm down, yet Askin can't believe Haschwalth is unfazed by what he sees. When Yhwach destroys the throne room, Askin grabs onto a piece of the rubble for dear life. He shouts at Haschwalth, pleading with him to get Yhwach to stop.
Later, after Yhwach transforms the Royal Palace into Wahrwelt, Askin is seen kneeling before him in the new throne room along with the other Sternritter. When Ichigo and the others invade Wahrwelt, Askin confronts them, lamenting his luck. Muttering that it could have been worse if he had gotten the whole of the Gotei 13, Askin notices Grimmjow attack him from the side before crying out in shock as the tower he is standing on explodes.