Sure, Wizards might have allowed Hypnotic Specter for a while (it was eventually banned) and banned Serendib Efreet, but I'm not bitter
Junji, the Midnight Sky Junji, the Midnight Sky has powerful death triggers that make it an annoying threat
Chaotic by name and chaotic by nature, in Spiral Chaos you'll find frogs with every ability under the sun, foot tokens, and expensive artifacts that let you pay nine mana to simply "choose a number"
Many of these interactions allow you to win the game outright, changing the game to one of racing towards a combo, or denying the opponent the same
Even when they did, using that to cast an early Wrath of God, drawing ramp in the late-game was often detrimental
This means that whenever you cast a Human, you receive two Humans instead, functioning quite well with kindred-based cards that are more effective with large quantities of creatures