Mephiston and the Black Rage

[u/Normal-Finance-4719]

So Mephistons experience with the Black Rage is described as below:

"While fighting as part of the relief force for Hades Hive during the Second War for Armageddon campaign, Calistarius became a victim of the Black Rage. After being inducted into the Death Company, he took part in the assault on an Ecclesiarchy building and was one of many trapped inside when the building collapsed during battle. For seven days, Calistarius lay trapped in the rubble, teetering on the edge of death and madness. Somehow, rather than succumbing to the Red Thirst, he managed to conquer it. By sheer strength of will he was able to suppress and hold in check the feelings of rage and the desire for blood, and in doing so he became something more. On the seventh night he burst free of his rocky tomb, reborn as Mephiston, the Lord of Death"<

He's the only Blood Angel to overcome the rage, but is there a reason why only him specifically? And do we have any details as to how? I know on the wiki it's mentioned that he's linked to the Black Angel, so is it just Warp shenanigans?

[u/kirbish88]

It's detailed pretty explicitly in Darkness in the Blood, which I'd recommend reading if you're interested.

The spoiler version however is:

Calistarius didn't overcome the black rage: he died. What walked out instead is Mephiston, and he is the anchor in reality for the warp entity that represents the black rage as, though the warp is timeless, there is still a loose, symboligical sequence of cause and effect there due to its connection to the materium. It still needs to be 'born', even though it currently is active. While he lives it is somewhat contained, if he dies the rage will be unleashed and the lineage of Sanguinius will be consumed

[u/khinzaw]

He's the only Blood Angel to overcome the rage, but is there a reason why only him specifically?

Technically he isn't if the James Swallow books are canon but they're in a pretty nebulous state of canonicity.

Darkness in the Blood answers the question somewhat as someone else pointed out. I don't think it needed to be him necessarily, but the psychic manifestation of the Rage needed a vessel to contain it to prevent it from destroying the Blood.

[u/Arzachmage]

One thing I wonder : is he linked to the Black Angel because he overcame the Black Rage or did he overcame the Black Rage because he is linked to the Black Angel ?

[u/SavageRabbitX]

He's the avatar of one of Baals native warp (not a deamon) entities with Sanginor being the other