Only situation I can see where this would work in your favor: you have creature control available but no permanent control. You're spending a card to "convert" creature control into permanent control for the weapon slot only - that's extremely situational, and even for Gravity elementals, it would be more efficient to just pack simple permanent control cards. Pulverizer and Deflagration work especially well.
Most decks don't pack just one of a weapon, so they can draw it more reliably. Unless comboed with something else, this card just helps your opponent.