Ive been saying forever that blizz should bring the old legendary style (shadowmourne, thunderfury, Sulfuras, etc) back, but change the name to "mythical" and make the color of the items red.
Give everyone their free legendaries, but also make a team of people work for ONE thing, for ONE player, to make the group better. This doesnt need to be obtainable in pvp. From a lore perspective, you dont need a mythical weapon for pvp combat anyway.