User blog comment:Tagion/Purgatory Knights Deck/Critique wanted./@comment-24870933-20141031203911/@comment-24965906-20141031204327

Yea, but there is a difference between Dark Energy and Soulguard that's important here.

Dark Energy prevents the destruction outright, and Demios requires destruction for his effect. Therefore no restand occurs, since the condition isn't fulfilled. Soulguard prevents the card from not leaving the field, but not the destruction, hence allowing for the S1 to survive and also to be used again for fodder.