Bumbleflower changes that opinion for me
Strong Attack stat and Dragon Dance made it a sweeper threat
Its too slow for anything but Commander, but its excellent there as a source of many continuous effects: cast from exile, card draw, life loss, and so on
There are advantages and disadvantages to all of them, but the ability to sweep your opponent's creatures while leaving your own Yasharn alive and playing Uro, Titan of Nature's Wrath for free has convinced many Four-Color Midrange players to include Yahenni's Expertise
There are endless possibilities as to what exactly these new booster packs could contain, but there are some specific things that the developers of TCG Pocket need to do to ensure the game's continued success in the months to come
The cheaper your spells, the more likely it is you can cast a card draw spell and cast the spells you drew in the same turn