Mega Charizard Y EX stands out as one of the best cards in the game, due to its moveset
Able to buff your Rats and provide card advantage, this card doubles as both a win condition and an engine for Rat Typal strategies
No Karn Liberated was ever cast by paying RRR, after all
Ally with Wyleth, equip him with arms, and draw tons of cards as you dispatch your opponents with martial superiority
As you can guess with the decks legendary theme, all of the new cards are legendary, with two being artifacts and the rest creatures (side note: theres nothing in the deck that cares about legendary artifacts specifically, but a few cards that are affected by Historic spells, which includes all artifacts, and Dihadas minus ability looks for any legendary card)