Horus Heresy/Heartwarming

From Galaxy In Flames "Secondly, the "mark" of Calth refers to the solar radiation burns suffered by many of the combatants, principally the human (specifically non-transhuman) troops. The last of these veterans to die, many years later, still refuse graft repair and wear the mark proudly."
 * Garro Nathaniel the loyalist Death Guard shooting down the fighters pursuing Tarvitz the last loyal Emperor's child, willing to risk death to protect him because of his love and faith in his sworn brother of another legion.
 * Sinderman defiantly broadcasting a sermon of Peace and Tolerance through the War Fleet of The 63rd Expedition, pleading for the Love and Kindness left in humanity, stubbornly defying Horus' megalomania, not to mention the seemingly-hopeless Grimdark of the 40K universe.
 * The arguments between Garro and Varren in Legion of One and how Cerberus is convinced to stand down, despite being driven utterly insane by months of fighting and the events of . "The Emperor Protects."
 * The Outcast Dead features possibly the nicest depiction of.
 * In Know No Fear, the anonymous narrator pauses for a moment to explain the other meaning of the "Mark" of Calth.

"Venantus: We march for Macragge.
 * The final conversation of Ultramarine Ventanus and Skitarii Arook in Know No Fear. Two warriors from two very different cultures, who had just won a desperate battle against the treacherous foe. Two men who are about to part ways, knowing they will never see each other again.

Arook: We stand for Mars. *pause* It means the same thing."