User blog comment:Ixarising/Rating Games pairing you want to happen in the story./@comment-71.108.70.155-20131127185241/@comment-1359322-20131129091210

Truth be told, we don't even know if servants can trade for the Evil Piece inside their body with the Evil Piece they gained their own Evil Piece. One of the two possible candidate for your theory, Tannin hasn't done that after all.