Mastery of the Unseen is good when theyre removal-heavy, but when you have Arbor Colossus and Hornet Queen you might not need to go that big to win, and it can be slow to catch you up
Enchantment Color tag templates(None) Shared Animosity Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it
If youre running snow lands, getting this enchantment out is easy, and, unlike other white removal spells, theres no penalty associated with On Thin Ice
Without easy ways to flicker this commander in mono-black, you cant really do too much with its amass ability either
Honorable Mentions: Altered Ego, Angel of Jubilation, Anguished Unmaking, Archangel Avacyn, Avacyns Pilgrim, Ghost Quarter, Grafdiggers Cage, Gavony Township, Mentor of the Meek, Parallel Lives, Primal Surge, Rooftop Storm, Snapcaster Mage