User blog comment:Skeith9/Heroic Spirits Speculation/@comment-175.143.156.204-20140628040923/@comment-175.143.156.204-20140628161621

No What I'm proposing is not the Immortality, power he has from League of Extraordinary Gentlemen, but a different kind of power. As I said earlier, the Horcrux like portrait noble phantasm makes Dorian Immortal in the sense, if he is killed or has his artificial spiritual body destroyed in battle His spirit won't be absorbed in to the grail immediately. Instead it will be absorbed into the painting. Basically the painting will serve him as a secondary spiritual container.

Look I know that in the original novel the picture was supposed to represent the reflection of his morality, and only keep him young, but When I read the novel I saw that it is hinted that His soul still lives in the painting. So Yes It may not make him invincible (infact it does makes him far from immortal), but once his master has enough mana, He/She can resummon Grey in to a new spiritual body and continue fighting on the fields.

So look the only way to ensure victory is to Destroy the painting or Gery's Master while the fool is stuck in the painting.

Look As I said, I know this still sucks and make no sense but, once I have more time and work on it, I think you'll love it and will reconsider.