Life on Baal is something that, at first, weeds out the weak, leaving the lucky and the tough. Soon, the lucky die, leaving the tough. Leonadist was one of the tough. Through a combination of his skills and teamwork with his dearest friend, who he loved like a brother, Leonadist managed to survive life on Baal, and soon enough, managed to survive the Initiation Trials. However, not until one faithful day did Leonadist gain the rage that allowed him to ascend to the ranks of Deathwatch.....
Kneeling down, eyes closed, his helmet by his knees, Leonadist listened to the Apothecary inspect the gene-seeds of him and his battle-brothers, deciding who would live and die. Today, some of our battle-brothers have succumbed to the flaw within all of us. They will fight one last battle in defense of the Emperor and the Imperium of Man. You may rise Standing up, Leonadist began looking around, not letting his feelings show on his face Cloten!? Where is he? Looking around for his friend and brother, Leonadist realized the truth. He was gone, and had entered the ranks of the Death Company.
Less than 5 hours after that, the Blood Angels Expeditionary Force did battle with a army of Chaos Space Marines. They managed to win, but not without heavy losses. Instead of leaving the battle, Leonadist searched for a day and a night for his fallen friend. Finally, he found him, surrounded by fallen agents of the Ruinous Powers. Reaching down and pulling of his helmet, Leonadist put on the helmet of his dead once-companion, and added the name of Cloten to his battle scroll.
Since that they, Leonadist goes into a suicidal rage when the time of battle approaches. He suspects this is to see his fallen friend once more beside the hand of his Primarch. This can drive fellow Space Marines who do not share the Red Thirst mad.