Shadowverse [Free] is easily one of the best CCGs on mobile right now, and it has managed to stand apart from the juggernaut that is Hearthstone despite their similarities. Today, Shadowverse's card collection has grown because of the addition of the new expansion called Rise of Bahamut. You can see all the cards from Rise of Bahamut here and either admire or hate the art depending on your taste. I like it personally because it feels different enough from other CCGs I play - although I know there are plenty others that use similar art. The new expansion brings new mechanics to the game, such as Enchance and Clash, and should entertain the game's players quite a bit.
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In addition to the expansion, Shadowverse is adding some new prebuilt decks you can buy, which is an easy way to get your hands on viable decks without having to buy one card at a time. The developers are also trying to balance the game based on match data, which they talk about extensively here. So, if you're looking for another CCG to play, now is probably a good time to dive into Shadowverse.