You cant sacrifice the same Clue both to draw a card and to pay the cost of another ability (like Lonis, Cryptozoologists, which lets you sac clues to steal cards from your opponent)
Here is a Mewtwo Level X i found on google
We buy collections no matter how large
Dog // Cat Token Tokens 2 Dog // Cat (traditional foil, new art) 2 Cat (BNG) // Warrior (AKH) 1 Cat Beast (ZNR) // Shapeshifter (2XM) 1 Cat Beast (ZNR) // Rat (C17) 1 Cat (SNC) // Rat (C17) 1 Cat (SNC) // Dog (SNC) 1 Cat (C17) // Citizen (SNC) 1 Cat (C17) // Dog (SNC) 1 Cat (AKH) // Dog (SNC) 1 Cat (AKH) // Citizen (SNC) 1 Shapeshifter (KHM) // Rat (C17) These cards feature paws -itively wag -nificent new art by Allison Carl, Alayna Danner, Jakob Eirich, Nicole Gustafsson, Fiona Hsieh, Jack Hughes, Nana Qi, and Andrea Radeck
I think I can find a nice balance without making a deck thats terrible or oppressive
Enchantment Thelon's Curse Blue creatures don't untap during their controllers' untap steps