Leandros was once a soldier in the Ultramarines' Second Company. In the plot of Astartes 1, he was also a member of Titus's command group.
However, later, because Titus, as the Second Company Captain, showed disobedience to the Astartes Codex during battles with Orks, and because of Titus's repeated contact with Chaos power, Leandros reported his Captain to the Inquisition. This led to Titus, as the Captain of the Ultramarines' Second Company, one of the nine founding battle groups, being arrested and imprisoned by the Inquisition. For the next hundred years, he was constantly tortured and interrogated by an Inquisitor named Trax.
It wasn't until Trax, as an Inquisitor, became corrupted by Chaos and was slain by the Grey Knights that another Inquisitor, inheriting his property, discovered Titus and many other Astartes secretly imprisoned by Trax. Considering that directly releasing these Astartes would cause intense conflict between the various battle groups and the Inquisition, this Inquisitor simply sent these Astartes directly into the Deathwatch. Those who were proven still loyal to the Emperor and the Imperium would choose to hide their names and origins, joining the Deathwatch to slaughter alien enemies in the galaxy. And Titus was one of them.
If not for Leandros's report, Titus, who was deeply trusted by Battle Group Master Calgar, might have already become the First Company Captain, or even the next Battle Group Master candidate. The above is Marcus's limited understanding of Leandros as a person. As for why this guy became a Battle Group Chaplain after reporting his Captain, Marcus didn't know.
All in all, to put it diplomatically, Leandros is a person who highly values the rules of the Astartes Codex and acts with extreme seriousness. To put it bluntly, Leandros is a pure Astartes Codex fanatic who thinks everyone else is disloyal.
Watching Leandros stride towards him, Marcus mumbled in his heart, guessing that the other party probably meant no good. A few seconds later, Leandros's tall figure was already standing in front of the iron door.
Taking the key from the Ultramarines guarding the door, Leandros opened the iron door and entered the room. Subsequently, Leandros stood in front of Marcus, gazing at him through his terrifying skull mask.
Marcus knew that showing weakness and avoidance at this moment would only increase the other party's suspicion. So Marcus raised his head and met Leandros's gaze as well. A tense atmosphere instantly filled the already small room.
After a moment of staring at each other, Leandros was the first to break the tense atmosphere.
"To the prayer room."
After dropping this sentence, Leandros retreated, and Marcus followed closely, walking out of the room.
More than ten minutes later, led by several Ultramarines, Marcus arrived in a room with a tall Emperor statue and various ceremonial instruments. The mortal servants who were praying there, upon seeing the Chaplain and Marcus behind him, first praised the Emperor a few times, and then quickly exited the room.
"Soldier, your regiment's accompanying Chaplain should have told you to kneel and salute when you see the Emperor's statue." Leandros's cold voice sounded in Marcus's ear.
Marcus was not the kind of person who cared about face and refused to kneel no matter what. Moreover, if he didn't kneel now, he would really have to kneel later.
Kneeling before the Emperor's statue, Marcus began to recite the praises of the Emperor from the holy text in front of him, as requested by Leandros. Leandros, meanwhile, lit the ceremonial incense and took out several ceremonial items, placing them around Marcus.
Originally, these tasks should have been done by the mortal servants. However, considering the combat power Marcus displayed on Kadaku, only a few Ultramarines and Leandros were responsible for this task in the prayer room.
After placing the ceremonial items, Leandros took the holy text from in front of Marcus and asked Marcus to continue reciting the prayers. Leandros held the holy text in his left hand and took out a ceremonial staff carved with intricate patterns and embedded with a skull at the top in his right hand. Leandros stood in front of Marcus, with his back to the Emperor's statue behind him, and began to loudly recite the contents of the holy text in his hand.
After several minutes of prayer recitation, the ceremonial staff in Leandros's hand suddenly emitted a gentle white light. Then, Leandros lightly touched Marcus's forehead with the ceremonial staff in his hand. Feeling the warm sensation coming from his forehead, Marcus did not stop reciting the prayers. It was Leandros who stopped reciting and silently stared at Marcus.
It wasn't until several minutes later, when the incense in the prayer room burned out and the white light on the ceremonial staff faded, that Leandros withdrew his gaze. And Marcus also stopped his recitation and looked at Leandros.
"Under the Emperor's witness, I found no signs of Chaos on him." Leandros said calmly to the other Ultramarines in the room.
One of them immediately exited the prayer room to contact Acheran. Then, Leandros put away the ceremonial items in the prayer room.
Then he looked at Marcus and said, "You once told Titus that you had a dream about the God-Emperor. Now, tell me the content of that dream as detailed as possible."
Marcus didn't hesitate and told Leandros everything he had dreamed when he first transmigrated. However, Marcus cleverly omitted everything about transmigration and the system panel. He merely stated that he gained his current power after waking from the dream. In a sense, Marcus didn't lie; he just deliberately spoke vaguely in terms of expression.
While listening to Marcus's narration, Leandros carefully observed Marcus's facial expressions and demeanor. As a Chaplain responsible for supervising the psychological well-being of battle group brothers, Leandros could determine whether a person was lying based on their facial expressions. And he did not feel any hint of lying from Marcus.
After listening to Marcus's narration, Leandros fell silent. He was not a psychic unit like a Librarian, unable to directly probe the other party's memories through psychic powers. So he could only make judgments based on Marcus's narration.
Fortunately, Marcus was facing Leandros, an Ultramarines Chaplain who adhered strictly to rules and regulations and greatly valued the Gene-Seed Primarch's commands, so he didn't have to worry about the other party using methods like torture. Ultimately, Leandros chose to temporarily release Marcus and did not label him as a heretic or chaotic. But at the same time, he did not explicitly state whether Marcus was truly blessed by the Emperor.
Before Marcus left, Leandros gazed at him through his skull mask.
"Soldier, I will be watching your every move."