Christy, Canine Shepherdess

Affinity for dogs (This spell costs {1} less to cast for each dog you control)

Trample, Lifelink

Dogs you control get +1/+1 and have trample.

As long as Christy is in the command zone, dogs you control have "{r},{t}: Destroy target artifact."

Megapartner (You can have any number of commanders if each has Megapartner)