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As you can see, the connections are similar, except that Faust is Brother Calistarius and Mephisto is Mephiston. Calistarius overcomes the Black Rage and becomes Mephiston, him over coming the Black Rage was achieved by him "selling his soul". This theory is further reinforced by the fact that, in the Blood Angels codex itself, it says (along the lines) "in over coming the Black Rage, he became something much worse". As in, he sold his soul to over come the torment of the Black Rage and in doing so became a demon, or "one of the Seven Chief Devils of Satan".
As of the 7th Edition Codex, Mephiston's suffered the nerf bat. He no longer has a MC-like stat line, he's essentially now little more a Space Marine Captain with ML3 and a little extra special rules. A tear shed in pity.