They require something that has read your specific 99, knows what's been printed in the last six months, and understands the gameplan you're building toward not the average pile
The downside is giving your opponent a token with the same size as the mana value
For example, if you play a Tortured Existence on turn one and your Hashaton, Scarab's Fist on turn three, you can potentially put an Archangel Avacyn or a Sheoldred, Whispering One into play on turn four
Top 20 Angels in Magic Angels are one expensive creature type
Mother of Runes Mother of Runes (AKA Mom) is the ultimate protection machine, and quite the effective rattlesnake
Absolute Justice and its leader, Sakazuki, focus on lowering the play cost of your opponent's character in play and deleting them depending on how low their costs are