User blog comment:Lias' Pawn/BlackBeard Theory 2/@comment-5601098-20140411193331/@comment-24552694-20140412074720

WhiteBeard's Gura Gura no Mi is mostly likely the only fruit Beside the Yami Yami no Mi  that Blackbeard. Also there stands to reason that BB's Fruit stealing/simulating powerrs have certatin limits and conditions. As such he cannont randomly steal powers left and right, as it may infact cause him harm. Power always comes at a price.