A few words about the chapter
The Chapter was created for Crusades, to defend innocent people while cleansing, purging and burning the heretic and alien filth, yet their kind nature and their faith in their chapters creed made them really patient and kind, respecting the dead from either side of conflict.
Although their primarch is unknown, they do not even know if he is alive or missing, they know that he was a paragon of virtue, faith and responsibility, but had a great flaw, his wrath had to be tempered and mastered or else a space marine could have such a bloodlust that he would fall in Blood God's filthy grasp, therefore the marines of the chapter constantly meditate and head the creed wholeheartedly.
The Chapter's Creed called the Creed of the Diligent Patience, stating that you must be slow to anger and use your wrath to give yourself an advantage, have patience in everything thrown your way, have the resolve to do everything asked of you and do what you feel is right, have the willpower to stand up for the weak and your faith against the heretics and aliens.
The chapter's specialty is the siege doctrine, using it both offensively and defensively they are the masters of their craft, they are also the masters of heavy infantry and walkers, they are sure to form a spearhead with heavy flamers, bolters and meltas while their walkers are either raining fire from above or charging in the fray, their preferred weapons are the heavy flamers and bolters for ranged combat, for close combat they prefer their double bladed chain-swords and if the need arises a claw or a lance, some specialized units such as the 2nd company has only meltas, flamers, lances and claws, the Knight Crusaders which is the 1st company veterans and the chapter master's honor guard prefer to have a simple bolter if the need for ranged attack arises, storm shields and double bladed chain-swords.
The Knight Crusader
The Knight Crusader Nektarios, the chapter master of the Royal Iris Crusaders was giving a speech to the aspirants outside The Temple, the Fortress Monastery of his chapter in his medieval homeworld of Cynthia, a "moon" on the Centauri System. The mossy green rock of the mountain and the forest nearby made the position well guarded from the elements as well giving the high ground if the need for defense arises. The nearby river was pure and some tests were going to be made there for the aspirants, after all the river's mighty currents were no joke. When he finished his speeh memories of his time as an aspirant flowed through his mind.
He was the son of an simple apothecary in this medieval world, he did not know much about the outside world and did not really care he only wanted to be pure to his church, learn his father job and marry the girl he was eyeballing for a while... alas none of those things were meant to be since a Chaos War band destroyed his hometown taking the girl hostage and crippling his father, he did not stay idle while those things happened he knew how to use a sword no matter wooden or not, he knew the pressure points on a human being but his opponents were not human they were mad with rage, a bloodlust he had never witnessed before, the church had a legend regarding blood stained berserkers destroying, pillaging and slaughtering every living thing rather than taking it hostage, they were sent from the blood one, the god of Hatred Khorne.
As valiantly as the 18 year old man fought to protect his girl and aid his father he was simply smacked in the face again and again by the oppositions armor, every time he fell and coughed blood he rose again unleashing his wrath again and again, it was futile but he would not retreat nor surrender, but his father was losing ground way to quickly and soon a sound of cracking bone and a shriek of pain echoed in his ears, the left of his father was shattered, at that time the berserker he was facing punched him in the solar plexus rendering him unconscious while throwing off is feet 10 meters away. When he woke up he show men clad in black and purple robes wearing a similar armor to that of the Berserkers, iris color a high gothic numerical on their left knees, the Space marine chapter of his homeworld the Royal Iris Crusaders made short work on the heretics but they could not save everyone from his town including his girl.
After a while and while a captain of the chapter and a librarian were treating to his wounds and testing him for chaotic corruption, the librarian, named Charon, witnessed the lad's willpower and resolve against the invaders, he had a small talk with the captain named Veselin, it was decided that this lad, Nektarios, was to be an aspirant astartes. They went to the fang inside a land raider crusader, Nektarios was amazed with all the things he was slowly grasping and he knew that this was something major. When they reached a metal clad camp they stopped this was their destination, The Fortress Monastery of the Chapter, The Temple. There he met with others his age, some of them were harsh in both character and appearance others were sly and quick-witted but none had the diligence and patience Nektarios had that was obvious from the tests they did, and the knowledge they were slowly acquiring. After months of physical and psychological training it was time for the test to become squires, neophytes, to the chapter, The test sounded simple, you are going to battle two opponents at once, one on a psychic level and one a physical level. Nektarios was meant to go first since that was his faith or lack of luck he did not know which yet. He marched to the center of the proving grounds and his opponent revealed himself, he stood there dumbfounded, his opponent was the girl, his girl, Lydia, now clad in the inquisitions armaments, she had been saved by the librarian Charon and was sent to the inquisition since she was a powerful psyker she was meant to test him under the orders of The chapter and the Inquisitor Brand. He instantly figured out why her and why now, after all the marines of this chapter were given time to see their families and time to make one if one wished, Librarian Charon knew of Nektarios's desire for Lydia and could not think a better opponent for him than her. But time was of the essence and he had to get through this test and become a Royal Iris Crusader, he got his handcrafted wooden sword, cleared his mind and waited in a defensive stance, he felt the girls power trying to immobilize him and then finish the test with her wooden dagger but that was not going to happen with a sharp exhale he leapt towards her, fainted an upwards strike and immediately slide under her legs pulling her with him, she was anchored though she flinched at the faint, but instantly anchored herself to the ground with her powers and now she was ready to counter attack or at least that's what she thought but she was a second to late and Nektarios was up and managed to dodge her, he made a thrust gaining ground, but Lydia managed to immobilize him using the full extent of her powers and went in for the finishing move, he was angered and furious he could not wait for his wrath to subside to fight patiently or rationally at this moment, so he used his wrath to get free to counter her, they both hit each other's neck's with their weapons and fell to the ground, but after a split second Nektarios was up seeming not have realized why he was knocked down in the first place and picked up Lydia carefully, at the sight of this Librarian Charon unleashed a psykic attack to the aspirants mind it was time for the real test. Charon Bombarded him with different scenarios of how he could die lose Lydia or become a heretic, Nektarios responded to all these stimuli with the same tactic, prevail in saving innocents and his comrades or die trying, nothing was alluring to him about the Ruinous Powers, actually he felt hate and disgust and when he saw that he, Lydia or one of his comrades bend the knee to those Powers rage and diligence filled him in those scenarios either everyone lived as a loyal innocent or died. That was the result Charon announced to the former Chapter Master, Nektarios was about to be a very important Space Marine and Lydia an excellent Inquisitor.
Becoming Chapter Master
Nektarios had many campaigns under his belt but this was the most brutal and Decisive for the young Crusader. The Battle of Karhan, Khorne Berserkers and Dark Eldar Made a small alliance to destroy the imperial forts on that planet, The Royal Iris Crusaders were tasked with defending and then counter attacking the filth alongside the Inquisitor Lydia and her men, Nektarios and Lydia stood side by side while the were defending the inner keep of the Old Fort they were standing in, Berserker after berserker and Dark Eldar after Dark Eldar fell in this refined space from bolter and chain-sword, they were defending well and the enemy ranks were starting to thin out, it was time to make the spearhead formation, The Venerable dreadnoughts of the Chapter were here ready to deliver punishment with their flamers and lascannons and nemesis power swords, behind heavy armored companies rushed and to the enemy stronghold, The victory for the Chapter and Inquisition was assured or so it seemed, the attack on the Old Fort was a distraction the Opposition managed to summon a blood-thirster and the Berserker Champion was very pleased that he could have more blood and bone to walk over, while the Dark Eldar Archeon directed the mandrakes to assist the daemon. It was a most fierce battle but the Royal Iris Crusaders knew where to hit and hit hard, the dispersed the blood-thirster from the Berserkers and went on destroying the Dark Eldar Camps. That was the tactic from the Chapter Master but it was not that wise since he died by the deamon's powerful swing of the axe and and was eaten by it, at that gruesome sight the Chapter lost some of its fervor and started to lose ground, it was at this point and time that Nektarios was so angry and so determined to kill the daemon and drive the filth into their graves that he took temporary command of the operation and ordered the Dreadnoughts to raise the camps alone while the heavy infantry deal with the berserkers and Dark Eldar troops, so the Dreadnoughts could surround the enemy troops and annihilate them, while his Squad along with the guard of Lydia would kill the mandrakes and the demon. Witnessing all this the Dark Eldar Archeon went off world in his shuttle along with his guard and went back to their kabal. Meanwhile the Chaos Champion was enraged and secretly happy that he would kill so many of them and that he would die for his god, his bloodlust was matched only by the daemon he summoned, so he charged to aid his fellow berserkers. At that time Nektarios and Lydia's squads were surrounding the mandrakes ad the daemon, the mandrakes were easy prey against the heavy flamers, bolters and meltas but the daemon was not greatly amused, it wanted only to kill, maim, slaughter and that is what it started to do with one swing ten guardsmen died, with a second half the squad of marines did Nektarios charged at the beast, double bladed chain-sword cutting the flesh and sinew while Lydia was confusing it with her powers and bolter shells, a while after the daemon had one less leg so it decided to fly, Nektarios sensed this and climbed the other leg driving the blade home to the beast's chest there he hold on for dear life as he was now at least 200 meters above the ground. Lydia could not reach the daemon and had a problem of her own the Chaos Champion appeared before her and charged her they started fighting, from behind the champions ugly head she could see black smoke rising and the Dreadnoughts appearing, she sensed that ultimately they won the battle and they needed only to clean up all the remaining enemy troops made a wall to halt the reinforcements marching towards Lydia and the squad of their temporary leader.
As the battle raged on a deafening shriek of pain and loud growling stopped everyone from what they were doing and made them search for the location of the noise, the Daemon was falling, it was falling fast and everyone could tell that it was lifeless, but were was Nektarios? Were was the Temporary commander of this operation, Lydia had no time to think about that as she was struggling with the Chaos Champion and was losing ground, she tripped and fell down, when she looked up she saw the ugly corrupted face of her enemy, he was about to kill her and then move on to the next target, as he rose the poisoned chain-axe to strike her down, she heard a psalm inside her head, it was a calming litany that was the Royal Iris Crusaders favorite, in that moment a large crater was formed, and the carcass of the daemon appeared, at that moment everything slowed down, she could define every little detail about everything in her line of sight but a shadow was getting bigger and bigger, then she looked up she saw that Nektarios had jumped before the daemon reached the barren earth and that the Chaos Champion was flat on the ground with impaled by the great double bladed sword the Crusader carried, she heard his voice, telling her to cut his neck with her dagger since this was her kill and he would like to honor that. She picked her dagger and stabbed it into the Champion's neck. After the clean up from the battle the Elder Crusaders, had a meeting debating about a crusader who took command at a time of crisis and won the battle, the result was that he would be promoted to Knight Crusader, Chapter Master of The Royal Iris Crusaders.