It gives us an experience counter when it comes into play, and with five experience counters, not that hard to get, we get to tutor every turn
You need to sink 3 mana to get two lands, 7 to get three thats just inefficient
For example, A Legendary Ocean in addition to giving Water monsters an additional 200 attack and defense reduces the level of all Water Monsters in the hand and on the field by one, making it possible to Normal Summon Level 5 Water Monsters without tributing and easier to Synchro and XYZ summon some cards
This card basically gives you an entire half of a new hand for almost free, and I cant think of a better way to climb back into a game or pull ahead of your opponent than casting this card
Each booster pack contains 10 cards and a code card for Pokmon TCG Live
Notice that all of these cards are typically even trades (ex: I play Elderfang Disciple, going down 1 card, everyone else goes down 1 card.) These aren't great on their own since it costs you mana to do so, and, in the case of discard and sacrifice, the opponent gets to choose an asset that they are least upset to get rid of, making them actually below-even trades