There are so many episodes of Doctor Who and only so many cards to make, that planechase gave us a few extra places
Blue mages also care about control and proving themselves the smartest, and their primary method of defending themselves is by outthinking the opponent represented in-game with countermagic that proves they held the answer before the opponent considered the threat, and card advantage that symbolizes how much the blue mage has studied
It also has ...And Beyond, which says that whenever this character quests, you may play a card with a cost of two or less for free
Since Heroic decks are built around stacking up the power on creatures, this makes Greatsword of Tyr a fantastic addition to the archetype.
The last ability you put on the stack will be the first one to resolve (As a result, you can have those abilities resolve in the order of your choosing.)
There are also a couple of great sites to check out and keep on the lookout for whenever a new set releases