If you believe your previous incarnation’s crimes were so vast and repellent then surely you know that there can be no redemption, that you shall never enter Paradise with the rest of the Faithful.
So there are two options.
Firstly, Mark yourself with the Black Dagger, and submit yourself to God’s Judgement, in the faint hope of absolution.
Or, alternatively, eternal servitude as an immortal monster guarding the Empire. Redemption is denied for you, but you can still serve and protect those for whom redemption is still possible. On that note, Aegis Militia are recruiting.