Cross Marian is Allen's teacher, a sorcerer and scientist. His most distinguishing features are his long, vibrant red hair and a Phantom of the Opera-esque mask on the right side of his face. In the manga, when Allen is rescued by him, he is in the appearance of a skull, after which the skull shrinks back and returns to being a mask. He is shown to be a gruff, demanding individual who is hard to please. He also has a habit of going into debt and making Allen (as well as anyone working under him or looking for him for that matter) work it off for him, and appears to be popular with women, with some characters calling him a 'womaniser'. It is revealed by Bookman that Cross has the unique ability to convert Akuma, making them work under his orders. The method of conversion is unknown, though it is most likely the power of the "Grave of Maria", which has been shown to control other characters in the series. Marian seems to be the only person the Earl is seriously worried about, a worry justified by the fact that Cross was able to slow down the download of the Akuma plant aboard the Ark. Cross has stated that he only lets clean people near him and can't stand filth, except if the dirty person is a gorgeous woman.
He left on a journey and stopped corresponding with HQ for four years. Allen fears him, which is hinted from the fact most of his flashbacks that connect to his teacher end with some kind of traumatizing (usually humorous) experience. It is implied that Cross and the Earl have met/fought a number of times in the past when the Earl saved Tyki from Cross and Cross's reply was "making a flashy entrance as always, fatso". It is known that before the 14th Noah's death, he and Cross knew each other. The 14th promised that if Cross looked after his brother - Mana Walker - that he would return, Cross revealed in the latest edition of the manga (chapter 166 and 167) that he believed Allen was the 14th.
He made his first real appearance saving his team from Tyki's new form on board the Ark, and then helps them restore the Ark. Although he tried to escape being sent back to the Black Order HQ, Lenalee's pleading for him to come breaks his resolve and he returns to HQ along with the rest of the Cross team and Tiedoll team of Exorcists. He is given a 'desk job' after returning, effectively a form of imprisonment. He later appears with the other generals to fight off Lulubell and her army of Lvl 3 Akuma. They succeed in destroying the Akuma and causing damage to the Akuma Plant. However, Cross is incapacitated along with the rest of the generals by the newly born Lvl 4 Akuma. Later, he disabled the Level 4 Akuma using Carte Garde and emerged from the rubble, injured but defiant. He then demonstrated that his strength is more than capable of standing against the Level Four Akuma alone, overwhelming it with fire from Judgement and forcing it to flee but still be destroyed.
Cross also shown to cares a lot about Allen, even though he called him Baka Deshi (idiot disciple) most of the time. In a recent chapter, he hugs a crying Allen after telling him about the 14th. However, at the end of chapter 168, Cross is shown to be badly wounded and possibly dead. In Chapter 169, it confirms that the incident was the last anyone saw of him, however his mask and his caliber revolver was left behind. This scene may imply that he is not truly dead, since his body was not confirmed as dead and immediately vanished without a trace.
It has been shown that Cross Marian wields two anti-Akuma weapons. While other Exorcists Generals have been known to carry multiple Innocence shards, Cross is the first to display the ability to use more than one Innocence shard at the same time. His skill with his Innocence is great as he was able to take down Tyki Mikk's transformed state without much trouble, while Allen couldn't so much as land a wounding strike.
- Judgement ( 断罪者 , Judgement): This equipment-type Innocence takes the form of a large caliber revolver with an undermounted barrel. Cross is able to fire several bullets in rapid succession, often emptying his rounds in a split-second. These bullets will not cease until they hit their target. A symbol in form of a cross can be seen wherever these bullets hit (even on barriers). Cross has also shown an attack ability called "Arrow Of Original Sin" ( 原罪の矢 , "Arrow Of Original Sin"), which forms the shape of a demon-like bow around Judgement as a cross symbol appears in front of it. This ability was used by Cross to attack the Akuma Plant. Recently, Cross has shown the ability to use Judgement at a "purging level," which allows him to launch a large, devastating attack with a cross symbol on it similar to the crosses made by his regular bullets
- Grave of Maria ( 聖母ノ柩 , Grave of Maria): This parasitic-type Innocence doesn't belong to General Cross himself, but to Maria, an Exorcist with a parasite type innocence. It has been remarked by Allen that Cross is able to use magic to control Maria's corpse during a fight therefore allowing him to also use her Innocence. It takes the form of a large, flattened coffin wrapped with a long chain. When the chain is removed, the coffin opens to reveal a beautiful woman in a fancy dress with a large bow tied over her eyes, which makes it slightly reminiscent of a butterfly. This 'woman' is in fact the corpse of Maria. With the defensive ability 'Magdala Curtain' ( 聖母ノ加護 , 'Magdala Curtain'), Maria uses her song to create illusions that can conceal the presence of others. She also has another ability called "Carte Garde" which allows her (or Cross) to control the person's movements by affecting the brain. Lavi has pointed out that Cross Marian's use of the "Grave of Maria" anti-Akuma weapon is unorthodox and forbidden