One mana to destroy a target artifact is already the best rate we can hope for, but 5 for a one-sided board wipe that's guaranteed to sink that Mishra, Eminent One deck is just excellent
Expect a lot of deal-making like I wont attack you this turn if and I can destroy that Propaganda if you attack them this turn. Honorable Mentions Casey & Raph, Hotheads, Donnie & April, Adorkable Duo, Mikey & Mona, Mutant Sitters, and Splinter & Leo, Father & Son each present a great opportunity to do good for others, and are a great bargaining chip
Later on Phyrexians would have more colour identities than the simplistic "villain = Black Mana" we have here, but it does fit with the idea of Phyrexian power being a dangerous, forbidden Pandora's Box to those that aren't actually receptive to its ideologies and power
Its so full of value that the built-in protection from their ward ability feels like an afterthought