TCGPlayer is currently your best bet since you can look at a ton of card stores
it's one of the strongest colorless ETB effects in the game
Each character deals damage to each other, and if the damage exceeds their willpower, they are discarded
9 Hades, King Of Olympus (Enchanted) - $101.75 Set One, The First Chapter What if Hercules had failed and Hades would have been allowed to stay King for more than, let's check the clock, two whole minutes
Whispers of the Muse (T1, Ext, S, Block) A favorite in "Turbo Xerox" (a blue deck which used minimal land but a ton of cantrips to thin out the deck), Counter-Phoenix (Shard Phoenix + Forbid) and Tradewind-Awakening (put Awakening on the stack, tap all your lands for mana, untap all your lands), Whispers has what might seem like a hefty price to pay for one card but you get to do it turn after turn after turn
I've seen some of them, and I've played some of them, but they aren't my personal top picks
