mtg cards with poison counters Potion Token Common (A player with ten or more poison counters loses the game.) A Common Disease – Building

If it does see play (which it may not, given the speed of the format today), it is likely to help boost some slightly slower decks and reinvigorate some that existed previously

Theres a smaller theme around artifacts and blue based control deck, but you really have to steer yourself into those two for them to come up

Many legendary cards have higher costs to compensate for their stronger abilities, so Kethis giving you a flat one generic mana less cost for them helps get you in the game faster

You see, Thespians Stage also has an ability that can turn it into any other Land card for two mana, but it also retains the ability to change again