|Spoiler Alert: This article/section contains details about future plot lines described in the light novels, not covered in the anime. Do not proceed unless you want to be spoiled.|
|“||You're fun, interesting, and exciting. I want you to damage me more and more. Then, I'll get even stronger from each hit.||”|
—to Kurumi Tokisaki
|Novel Debut||Date A Bullet|
|Anime Debut||Dead or Bullet|
Nicknamed Biscuit Smasher, Tsuan is infamous in the Neighboring World for being able to easily crush a Quasi-Spirit into pieces with as much ease as a normal biscuit cookie. After fighting against Kurumi Tokisaki in the battle royale, she becomes Kurumi's reoccurring ally and grows obsessive over the chance of a rematch with the Spirit.
Tsuan has light brown hair styled in two neat buns and possesses pinkish-purple eyes. In combat, she wears a dark blue qipao with a metal chest plate and twin greaves situated near her hips. Her outfit is also decorated with spikes on her shoulder guards, shoes, knuckles and around her wrists.
Tsuan is a fearsome warrior, revered for her battle prowess and kill count. Her infamy leads to most Quasi-Spirits avoiding her, or some attempting to kill her to take some of that fame. Tsuan, despite her reputation, isn’t necessarily a bad person. She has a somewhat unhealthy desire for battle and an insatiable thirst to improve herself and grow stronger. She loves to challenge herself against tougher opponents, and thrives on battle. It should be noted that Tsuan doesn’t limit herself to physical, bloodshed battles alone. Tsuan views everything as a battle, so long as there is a victor and a loser, and always strives to be the former of the two.
Before meeting Kurumi Tokisaki and battling with her, or at least Hibiki-in-Kurumi’s body, Tsuan never truly understood nor cared for the consequences of battle. She didn’t recognize those she killed as lives that she had taken, but understood them as a necessary evil of swinging her Unsigned Angel. Tsuan didn’t fight out of malevolence, she fought for victory. Any consequences of that victory were inconsequential to her. However after that battle, Tsuan realized that victory meant more than a badge of honor, and aspired to best Kurumi in a battle to the death.
After meeting Kurumi, Tsuan became obsessed with the idea of fighting against her and ultimately killing her. She originally fought Hibiki-in-Kurumi’s body, and found that battle to be both exhilarating and euphoric. Upon finding out that she was battling a “fraud” and not the real thing, Tsuan swore that she would fight the real Kurumi Tokisaki, believing this to be an ultimate honor and achievement if she had the ability to surpass a Spirit in battle. This drive led Tsuan to pursue Kurumi, shadowing her throughout her journey between Regions and going as far to participate in the idol contest against Kurumi, then again with her under the promise that Kurumi would fight her if she assisted her, showing just how profound this desire is for Tsuan.
One of Tsuan’s most admirable traits is likely her perseverance and motivation. Her Astral Dress, Brinicle, is a physical manifestation of this. Tsuan is often compared to an animal in the novels, and this comparison is apt. With her enhanced senses and beastly relentlessness, she is a force that, when she puts her mind to something, requires a massive amount of effort to be stopped. Even when bested or brushed aside, Tsuan doesn’t let these occurrences phase her and continually strives to achieve her goals. Her desire to improve herself and have a passion outclasses many of the Quasi-Spirits shown in the story.
Tsuan is also perceptive. Perhaps as a result of her enhanced senses, Tsuan is shown to have an incredible ability to perceive threats or understand tense situations in the blink of an eye. Her battle prowess and reactions are all fine-tuned and honed well, giving Tsuan a large advantage in a variety of situations.
Aside from these qualities, Tsuan comes off as both intimidating and quaint most of the time. Her habit of sniffing people and glaring unintentionally often puts others on the back foot, though she insists she doesn’t mean anything ill of her actions.
Tsuan arrived in the Neighboring World with no memories of her old life besides remembering her name. Seeing the weapon in her hands, she realized that her mission was to fight. However, at first she got scared and ran away in fear. Picked up and taught by Haraka Kagarike, Tsuan developed her talent for fighting and was able to live her new life in the Neighboring World without any major issues. 
Powers and Abilities
Weapon: Halberd-Warhammer hybrid
According to the information card in Date A Bullet 1, Lailaps has the ability to destroy matter at the particle level, thus earning her the nickname as Biscuit Smasher.
Another ability from Lailaps is enhancing all her senses, making her like a hound. She is able to sense Yui Sagakure's Reiryoku from a distance even when the ninja is using stealth ability of her Astral Dress.
Her Astral Dress Brinicle also has an ice ability. When damaged by an attack, the shards will instantly freeze the area surrounding her wounds, including her opponent if they are within range. The freezing effect becomes stronger the more damage it sustains. It can also be used to freeze her wounds and stop bleeding. However, doing so also puts her at risk of frostbite. At full power, it can even summon a small blizzard to temporarily blind the enemy.
After returning to the real world, Tsuan loses access to her Astral Dress and Unsigned Angel. However, her trained physical prowess is retained.
- Light Novel
- (To Kurumi Tokisaki) "Thank you very much. Thanks to you, I can grow even stronger." 
- (To Kurumi Tokisaki) "Indeed I understand. This is Tokisaki Kurumi's love. It's not the same shape as my love, but your expression is interesting, amusing, enjoyable, and most of all, beautiful and exciting. So show it off more often." 
- (To Hibiki Higoromo) “It's fine. You won't die even if killed. I guarantee.” 
- Tsuan's Unsigned Angel <Lailpas> refers to a Greek mythological dog who never failed to catch what he was hunting.
- Brinicle, also known as ice stalactite, is a downward-growing hollow tube of ice formed beneath sea ice.
- In the Date A Bullet anime, her name is romanized as Tsang.