Great picture.I definitely get what you're saying, it would make a lot of sense for them to be friends because they have so much in common, but I don't think they were. I do agree that Sanquinius probably cared about Curze, but he was just a nice guy who cared about all his brothers, wasn't he? The lore shows that Curze was civil to Sanquinius in their conversations, so officially he didn't hate or like Sanquin. But I believe that Curze might of actually hated Sanquinius. He was everything that Curze wanted to be, but wasn't.-Sanquinius created lasting peace and justice without using terror and ruthlessness. -Sanquinius' home planet and people loved him and remained good due to leadership. -Curze's planet constantly fell back into chaos and it's people remained as cruel animals who were only controlled by fear.-Sanguinius was loved and accepted by all. -Curze was feared and judged and his own brother did not accept him. -Sanguinius' sons were noble and respected. -Curze's sons were barbaric killers that he himself despised. -Sanguinius could (mostly) control his psychic powers and they gave him strength. -Curze could not stop his psychic visions and they brought him nothing but pain and sadness. -Sanguinius was pure and uncorrupted. -Curze was traumatized, looked scary and corpse-like, and had to sink to the same level of the monsters he killed.I think that part of Curze looked up to Sanguinius and another part hated him out of jealousy and his own self-loathing. In the lore, Curze said he hated his fellow traitor primarchs because they were corrupt and disgusting. So I'm positive that, even after the horus heresy, Curze must of had some respect for Sanguinius due to his purity and bravery.I don't know much about Sanguinius, but I'm surprised he wasn't closer to Curze. He could have tried to help Cruze with his visions since Sanguinius had much better control over his own psychic powers. Sanguinius also has an uncontrollable just like Curze, i.e. his Blood-rage. 1 big reason Curze was an outcast was because of his traumatic visions that he couldn't control. He might have been more accepted if he could have bonded with Sanguinius over their mutual curses.But I'm guessing Sanguinius hid his Blood-rage power, didn't he?Also, now that I think about it, Sanguinius and his honorable, pure nature might have made him dislike Curze for his ruthless and underhanded tactics. So, who knows if Sanguinius even cared much for Curze.Still, I do think they could have been friends in a different life