Regarding other Blood Angels of note, Caphriel has a scale of friendliness with them:
Astorath: Caphriel views their jobs as two halves of the same coin. They both must save their brethren; Caphriel from death and Astorath from themselves. The two have a grim respect for each other, and Astorath prays that Caphriel will not be claimed by his blade.
Mephiston: They see one another but rarely; working on opposite sides of the Arx Angelicum. If Mephiston referred to his relationship with Caphriel as “functioning,” Caphriel would be shocked that Mephiston thought of him so closely.
Dante: He sees Caphriel, and that worries him. So young, and yet already acting beyond his years with wisdom and patience. But this is the grim darkness of the far future. Caphriel could die tomorrow, today, within the next hour. His shoulders are already broad with the weight that he carries.
Even worse, when Caphriel looks at Dante, there are stars in his eyes. Caphriel wants to be just like him. Dante will go to every length to protect him from such a fate.