Ravenous Rats and Mesmeric Fiend were used a fair amount back in the day as disruption and value in Recurring Nightmare style rock decks
whenever you Proliferate, choose any creatures on the battlefield and add one counter of every type the creature has to itself
A perfect deck for players looking to play a fun, cohesive, themed deck.
Since it has offspring, you can get an extra copy of it on the battlefield
In case you've heard the term but don't know the cards, here's a rundown of the original Power Nine: Honorable Mention: Library of Alexandria, arguably Magic's most powerful land, rounds out most people's list of the Power Ten
Like most Magic: The Gathering cards, the value of Kaya, Intangible Slayer depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Phyrexia: All Will Be One)