The zero loyalty ability allows you to draw a card, which means it really gains you a loyalty, and the -2 ability creates a 2/2 blue Spirit that gets a +1/+1 counter on it every time you draw a card
Braingeyser Braingeyser can get out of control in a Vintage game when you have access to all the free mana that the Mox cards from the Power Nine produce
Avatar: The Last Airbender revitalized allies with more modern sensibilities, to the point where you can now craft different Commander decks around the creature type without just relying on General Tazri
On the other hand, Ad Nauseam was formerly a Modern staple, though power creep and the banning of Simian Spirit Guidewhich offered Ad Nauseam the fast mana it needed to actually win the gamemore or less killed the combo in the format
Miku has done collaborations with other major IP like Pokmon, has several video games, and is in the middle of an IRL world tour where she performs on a screen
Though Beza offers incredible rewards, getting them is problematic