Unlike cheaper planeswalkers, six-mana walkers wont typically pull you back from a losing boardstate, instead serving to cement an advantage or eke out a win from a tight game
City Pigeon is a card that enables web-slinging for green-white, but it's also great to modify on for white-blue
The [c]Circle of Protection[/c] cards are a mega-cycle of white enchantments that each cost two mana, 1 white and 1 generic
It might seem like this card has three different modes, but in most games you will be using either of the two more powerful ones: either kill a creature or kill a creature and make a 1/1 token
Being able to pay for a spell without mana has a huge effect on play
When it enters the battlefield, look at the top 9 cards of an opponent's library and steal 2 of them, it's basically like having Super Dig on a creature