13 Kokusho, The Evening Star Kokusho, the Evening Star is a legendary mono-black dragon that debuted in Champions of Kamigawa
If you are looking to doom scroll in the name of research, I would recommend
A safe rule of thumb for most decks is to keep your uninkable count between 8 and 12 cards (roughly 15-20% of your deck)
All of these cards can be cast for their front side casting cost, or the alternate More Than Meets The Eye cost, to have it enter the battlefield converted on its back side, similar to transforming effects found on many werewolf cards
Keruga, the Macrosage Keruga, the Macrosage can only be the companion for a deck built entirely of cards with a mana value of 3 or more
Things have gotten to a point where The Pokmon Company has had to issue a rare statement regarding these shortages alongside a promise that more cards are on the way