When you venture into Middle-Earth, flavorful abilities were ported onto the cards from that world, and annihilator was (fittingly) used on this equipment
Lastly, Yawgmoth, Thran Physician gives you an excellent way to both draw and discard cards, and his Proliferate ability goes great with the +1/+1 counters from Connive
It forces players to either leave up a blocker, or risk taking a significant amount of commander damage
Rares or mythics are best, because there are more foil copies of commons and uncommons floating around
Most notably, whenever you cast a creature spell, you create a 1/1 Human token with training
One of the Magic Rules of Magic Finance that I tend to repeat a lot is that I will always pay $4 per thousand on unseen bulk commons and uncommons and never more