Those who've played with Land Tax will tell you that while that's not a half-bad deal, they can go one step further: they can get three cards every turn for the rest of the game for the same one mana
Upon the nearest SBA check, Corrupted Conscience goes to the graveyard, and the opponent gets the Relic back
This synergizes great with something like Teeth and Ambitions, turning that song into deal 4 damage to your opponent's characters, either all to one character or split into two 2 damage pings
That said, you need a permanent-heavy graveyard deck to get the most out of the descend abilities, so this may secretly be a card
What about Phoenix Chick makes it so special
Recycling Fetch Lands is a solid use of Closet, while Cellar can provide a big value burst in the late game, given how much mana most green decks end up with in Commander