Crusade and Heresy
On Melchior, he tried to hide the Red Thirst from Raldoron and Sanguinius, coming to a heated discussion with the First Captain. Shortly after Jaghatai Khan's purge of the Nephilim, Sanguinius chased down his brother to speak with him. It was Azkaellon that welcomed the Khan aboard the Red Tear. At some unknown point, he duels Lucius. Though Lucius draws first blood, winning the duel, Azkaellon tackled him over the side humiliating him in front of his men. Before the events of Signus, he led a task force, including Meros, to a world being raided by the Dark Eldar. The true purpose was in hopes of finding a cure for the Thirst, which they did not. Also he is the one who woke Meros up from his sarcophagus dream-talk with Rafen. At Signus, he was weary of the Space Wolves and Word Bearers. He got real protective of the Great Angel during things. He also covered up Nassir Amit's Thirst induced murder of the Wolves, showing that he can be a bro at times. During the Imperial Secundus, he selected Sanguinius new Herald, who may have eventually became the Sanguinor. He lost an arm to during when Sanguinius tried to save him. To note, the explosives used were originally intended to protect Sanguinius. He later had to set fire to a library on the Red Tear after it was corrupted by Daemons. During the Titandeath at Beta-Garmon, he and Amit, along with there respective units, boarded a Starfort, named The Anvil. They briefly captured it, before realising it was a trap.
Siege of Terra
He grew worried about Sanguinius' attempts to inspire the conscripted Army forces. He along with his Primarch and an escort of Sanguinary Guard went to save the Khan from the Death Guard. In the end, Sanguinius would leave Azkaellon on Terra when he went to fight Horus.
Azkaellon was the last member of the Sanguinary Guard, he later reorganised it and the Blood Angels into Successor Chapters. He later disappeared, leaving Raldoron as the Chapter Master of the Blood Angels. Also, the Blood Angels have a class of ships named after Azkaellon.
Azkaellon was incredibly loyal to Sanguinius, basically an over protective mother. He also told Raldoron that he would sacrifice any warrior to protect Sanguinius. He and the Guard were seen as being too rigid, a point of conflict between the fluidity of Raldoron and the First Company.