There was once a more social and, for lack of a better term, likeable version of Asumu, however, one that existed both during his rise in the Wandenreich's ranks, and before he betrayed Fenrir, the King of Wolves. In those times, Asumu was more concerned with the individuals as opposed to the species as a whole. Bonding with others and making new companions was one of the things he enjoyed most during that time, and while he did slowly start to grasp a much larger picture of the Quincy's situation, he never did lose this desire. On the flip side however, Asumu also desired strength and power; not to use for destruction, but rather, to use for protection, of both himself and the ones he could call "friend". It was this desire for power that led to his downfall, and a change in perspective; he then started to believe that friends should not be sheltered, but should instead be helped and allowed to carve their own path.
Asumu is a man of order and loyalty, never questioning the law, and never betraying those who trust him. To Asumu, the continued existence of a ruling government is the key to survival and prolonged existence of any being, hence why he is so dedicated to the cause of Yhwach and his Wandenreich. The survival and prosperity of his race, the Quincy, is his primary goal, and it is a goal that he is willing to achieve at any costs necessary. Neither Shinigami nor Hollow can stand between him and his ultimate ideal: a world where the Quincy reign dominate over all other races, united, and no longer under the threat of extinction.
Those who are outside the Quincy race are either seen as a respectable enemy, or something that is simply not worthy of his attention. While he does hold most other races in a lower regard than his own (like many other Quincy), this does not mean he underestimates them in any regard, but rather, sees them as socially inferior to the Quincy. He cites the Shinigami's wreckless genocide of the Quincy, and their refusal to negotiate as a prime factor of such behavior, and generally perceives Hollows and Arrancar to be nothing more than just animals. His perception of individuals within these races may be subject to change depending on their behavior around him.
Contrary to the majority of his fellow Sternritter, Asumu carries a code of honor about his person during battle. He prefers to fight against opponents who are of equal if not greater skill than himself, and wishes to fight with the skills that he is best suited for, and expects the opponent to do the same. He will only fight a disarmed opponent if they wish to do so, but otherwise, he will often allow, even force his enemy to recover their weapon before continuing the duel. Fighting against weaker enemies is something he prefers to leave to his subordinates if possible, but he is a man who admires a strong will, and will grant a weaker enemy a chance to fight him one on one. Asumu is also respectful to opponents who have fallen at his hands, but were capable warriors themselves, as he will burn their bodies after death and allow their ashes to scatter into the wind.
His interests include writing, archery, dueling, and wine-making. His favorite food is fried rice, while his least favorite is anything spicy.
- Heilig Pfeil (神聖滅矢 (ハイリッヒ・ブファイル), Hairihhi Bufairu; German for "Holy Arrow", Japanese for "Destroying Arrow of Sanctity"): The primary and signature ability of all Quincy, Asumu can generate his Heilig Pfeil arrows by aiming his Spirit Weapon at his target and generating two "arms" from it's blade, making it resemble a crossbow of sorts. These arrows are fast and powerful, with one of them capable of destroying a single building within Hueco Mundo.
- Heiliges Feuer (神聖滅火の手 (ホーリーファイア), Hairihhi Faia; German for "Holy Fire", Japanese for "Sacred Destruction Flames"): An ability that is only usable by Pure Quincy. Asumu condenses his Spiritual Energy into his blade and can then generate azure flames as a result. These flames can be used to inflict major burns on his enemies, and they're also used as a surprise attack as well. During the Wandenreich's first invasion of the Soul Society, the Sternritter used these flames to initialize their attack against the Shinigami. Asumu can also use this technique as a landmine of sorts, simply by slicing the ground near him and imbuing it with the condensed flames, and then letting the foe walk on top of it, which then causes the flames to shoot upwards in a massive pillar, engulfing and destroying the target utterly.
- The Lunar: Harbinger (ス ルナー: ハービンジャー, Su Runa: Habinjaa): Harbinger is the only named ability of "The Lunar" that Asumu can use, and it is only capable of being used when Asumu is in his full powered werewolf form. By taking his Quincy cross in his hand, Asumu forms it into a bright ball of energy that he aligns with the moon, before tossing it into the sky above him. It then proceeds to fire a beam of energy down at Asumu and he emerges in a slightly weaker version of his Quincy: Vollständig. Typically, this is an easy way for Asumu to access his most powerful state and abilities without having to wait on a full moon, however, it is not as strong as it would be on the night of a legitimate full moon.
- Blut Einklang (血装協調 (ブルートきょうちょう), Burūto Kyouchou; German for "Blood Harmony", Japanese for "Harmonized Blood Guise"): Previously, Blut Vene and Blut Arterie were incapable of being used at the same time. However, Asumu's Werewolf form is able to overcome this barrier due to his increase in power. With this, both Blut systems are able to be used at the same, making it to where Asumu can increase his offense and his defense at the same time.
- Enhanced Heilig Pfeil: When in his Werewolf state, Asumu's Heilig Pfeil become much stronger. Rather than fire them from his Spirit Weapon, he instead forms his arrows, of which are now much larger in size, with his hands and throws them like javelins. Extremely powerful, these arrows are capable of pinning a Captain level opponent to a wall with little effort. However, because of their charge time, Asumu does not use them often.
- Enhanced Heiliges Feuer: The azure Reishi flames that Asumu can use also become much stronger when in Werewolf form. He now releases them from his mouth rather than from his weapon or hands, and due to the power and speed of the flames, he can cover a massive radius in front of him with this technique. It is capable of burning the sands of Hueco Mundo, something previously thought to be impossible.
- Ransōtengai (乱装天傀, "Heavenly Wild Puppet Suit"): By creating Reishi chords above him, Asumu is able to suspend himself and control his body if he were ever paralyzed or if certain parts of his body were broken. He is also capable of using this technique to control the body of his opponent when they themselves are immobile.
- Hirenkyaku (飛廉脚, "Flying Screen Step/God Step"): The Quincy's primary means of moving at high speeds, Asumu is a clear master of Hirenkyaku, able to move from various parts of the battlefield with relative ease. The blue flashes that appear as a result of this technique, when used in rapid succession, are known to disorientate his opponents.
- Kasaneawase Hirenkyaku (重ね合わせ飛廉脚, "Superposition of the Flying Screen Step/God Step"): Asumu begins this unique application of Hirenkyaku by first coating his entire body with a thin sheet of Reishi. When he uses Hirenkyaku, basically putting his body in a state of superposition, he "splits" himself from this Reishi sheet, which leaves a silhouette of himself in it's place composed of said Reishi, a "clone" in essence. He can create numerous clones and they are all capable of fighting Asumu's opponent, but they are only able to use basic abilities such as Heilig Pfeil.
- Kirchenlied Spellcraft: Considered to be the precursor of Gintō spells, Kirchenlied is used by Echt, or "pure" Quincy to create numerous different spells and attacks through the use of small rods kept in their uniforms. Asumu is a master of this sorcery, and knows some of the most deadly and powerful spells ever conceived.
- Kirchenlied: Sankt Zwinger (聖唱: 聖域礼賛 （キルヒエンリート: ザンクト・ツヴィンガー）, Kiruhienrīto: Zankuto Tsuvingā; German for "Church Hymn: Saint Ward", Japanese for "Holy Chant: Sanctuary Veneration"): Often hailed as the "epitome" of Quincy offense and defense, Sankt Zwinger erects a rather large mini-fortress of sorts around Asumu which protects him from outside harm. Should the target enter through the ward, they will be struck down by "the light of God". The true function of Sankt Zwinger is revealed at this stage: The ward itself is actually a marker, a crosshair of sorts for a large Reishi bow in the sky that is formed as a result of the Ward. If the enemy stays within the marker for too long, they will be binded in place of the Ward, similar to Sprenger, in where Asumu moves out of the Ward and leaves them stranded within it. The bow in the sky then fires a massive arrow down at the target, creating a large blue column of explosive energy that expands only as far as the Ward's radius, and completely annihilates the target within.
- Blut (血装 (ブルート), Burūto; German for "Blood", Japanese for "Blood Guise"): By pushing Reishi into his Blood veins, Asumu can either drastically augment his defense or his offense. Blut operates in two separate systems, one for defense and another for offense; however, these two systems cannot be used at the same time, forcing him to rely on one or the other. However, this is overcome when he enters his full powered Werewolf state, in where his strength and power have increased to the point to where both forms of Blut can be used at once.
- Blut Vene (静血装 (ブルート・ヴェーネ), Burūto Vēne; German for "Blood Vein", Japanese for "Stilled Blood Guise"): The defensive Blut form, Blut Vene grants Asumu inhuman endurance against any form of attack. It's strength is high enough to where he could stop a train in it's tracks. However, with strong enough force, Blut Vene can be torn and even penetrated, leaving the user helpless against more attacks. Blut Vene can also be used to seal wounds received by the user. Blut Vene is also incapable of blocking "wave" based attacks, such as Ikkotsu or Sōkotsu, which could both completely destroy an opponent in one blow.
- 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"): A more advanced version of Blut Vene, and an answer to the latter's drawbacks. By pouring much greater amounts of Reishi into his body, Asumu can make it possible for his very organs, muscles, and even his skin tissue to become harder than steel. Doing this gives him defense against any form of attack, including attacks such as Ikkotsu or Sōkotsu. Since this also increases his muscle strength, he is capable of both moving and attacking at the same time while using Stahlhaut. The only drawback is the time it takes to initiate the technique, which can take several minutes and must be done before a fight.
- Blut Arterie (動血装 (ブルート・アルテリエ), Burūto Aruterie; German for "Blood Artery", Japanese for "Moving Blood Guise"): The offensive Blut form, Blut Arterie grants Asumu inhuman levels of attack strength; however this only applies to physical techniques. With this power running through his veins, Asumu is capable of causing immense damage to even Bankai wielding Shinigami foes.
- Flight: Using his wings, Asumu is capable of flying in the air at high speeds.
- Sanrei Gauntlets: In Vollständig, Asumu's forearms are concealed by large, black and silver fingerless gauntlets with a cross shaped gem on their upward facing side. This is what Asumu uses to generate both his Heilig Pfeil and his Spirit Weapons.
- Reishi Greatsword: Asumu's already large Spirit Weapon becomes much bigger when he is in Vollständig. Rather than appearing like a rapier, similar to his original weapon, this sword takes upon the visage of one similar to the Reishi Broadsword used by Yhwach. It carries immense cutting power, easily capable of splitting a Captain-Commander level opponent in half should the opportunity present itself.
- Reishi Greatshield: Asumu generally uses his left gauntlet to generate a large, circular shield with a Wandenreich emblem embedded on it's forward facing side. While it is capable of blocking even some of the most powerful of attacks, Asumu can also use it to unleash a hailstorm of Heilig Pfeil upon his opponents, allowing him to both block their attacks and send out his own at the same time. However, the numerous Heilig Pfeil generated from the shield do not each carry the strength of his individual arrows.
- Enhanced Heilig Pfeil: His enhanced Heilig Pfeil do not increase in terms of power or strength, but unlike his previous Werewolf state, Asumu is able to generate them much faster while in Vollstandig, making them an even more dangerous threat to his enemies than before.
- Brotherhood (ブロセーフド, Burosehudo): Asumu's ultimate attack. When using this technique, the opponent must be looking directly at Asumu's body, his markings in particular. When he initiates the technique, the area around both he and his opponent becomes pitch-black, almost like an endless abyss. Asumu will then stand perfectly still and point at the opponent, and as he does so, a massive wolf composed of Reishi will appear in the distance and charge at the foe, attacking them with great ferocity. After one minute, another wolf will appear and will circle around the fight between the opponent and the other wolf, waiting until the latter falls before attacking the foe as well. In total, there are seven of these great Reishi wolves, and each of them grows stronger than the last one that fell before them. Should all of the wolves be killed, the abyss will break and they will both return to their original battlefield. However, Asumu will have gained more power from the deaths of the wolves and become all the more difficult to defeat. This does not last, however, as the powerup is only a few minutes, and should it expire, Asumu will revert back to his normal, human state, drastically weakened and incapable of using Vollständig for nearly two years. Asumu states that this technique is a "curse", and the embodiment of his worst regrets, though what exactly this refers to is unknown.