Angrath, Captain of Chaos is a great fit because he passively gives all of your creatures menace, making them more difficult to block, and can actively grow your Army with his loyalty ability
Instead, I want to focus on a huge new addition to the deck, the reason we are revisiting the archetype today, the card that just might make Gates the literal best deck in Historic: Spelunking
Rikku, Resourceful Guardian allows you to force a creature through your opponents' blockers, as well as steal counters, and Lulu, Stern Guardian protects you by putting stun counters on your opponents creatures, as well as proliferating to keep them around
However, you can work around this by 'resetting' finality counters
December 30, 2009