The master mages of Dalaran have gone too far this time, opening up hundreds
of portals! Choose a class and use a few spells and a WHOLE lot of portals to
defeat your rivals!
http://hearthstone.gamepedia.com/Too_Many_Portals!
可选职业 牌组内建7张随机职业法术和23张传送门
by Reddit
https://redd.it/4dmdou