Wizards are some of the most fun cards in the game. You can be confident when you see that a card is a wizard that it is going to be more than a boring 1/1 creature and because they generally have abilities that let you gain control they can become far more powerful than their generally small size would make them appear. In fact one of the only things in the game that is more feared than a wizard is a legendary wizard.
Linessa, Zephyr Mage is a legendary human wizard from the Future Sight expansion set of magic the gathering. A 3/3 creature that costs one blue and three colorless to put into play she is large for a mage and reasonably priced for a blue spell, but the real power of this card comes in its two abilities.
The first of these abilities costs two blue mana and X colorless, as well as tapping Linessa, Zephyr mage. For this you can return a target creature with casting cost x to its owners hand. This is an ability that is not as original as I might prefer to see on a legendary wizard but one that is reasonably powerful.
The second ability that this card has is that of grandeur. This is an ability specificity created for legendary creatures allowing you to far more safely play four of the legendary creatures in your deck. This grandeur ability reads "Grandeur - Discard another card named Linessa, Zephyr Mage: Target player returns a creature he or she controls to its owner's hand, then repeats this process for an artifact, an enchantment, and a land."
One of the important points to grandeur is that it does not require you to pay anything, you simply have to have the card in your hand, this means that you can potentially use this ability the turn that you play Linessa, Zephyr Mage if you have another copy in your hand, and if you do I strongly suggest that you do. Not only is returning a creature to the opponent's hand largely for free useful, but you are certain to hit a land as well putting them a turn behind in land drops and making it likely that Linessa, zephyr Mage will remain the largest creature on the board the next turn. In addition to this with less mana it will be far more difficult for your opponent to put out the two creatures a turn he or she needs to to stay ahead of linessa's ability.