While -2 defense on an enemy is in most cases worse than giving your hero +2 attack (unless you are doing some weird stuff with Straight Shot), Rivendell Blade's bonus still often boils down to 2 more damage being dealt more. That exchange is fantastic, with further advantages being that allies such as Galadhon Archer or Marksman of Lórien are also being viable targets as well as many of the most prevalent attackers in the game such as Legolas, Haldir of Lórien or Glorfindel.
Rating: 8/10
Decks of mine using Rivendell Blade