The third wing of Icecrown Citadel recently opened and expanded the Lich King's lair. The third wing contains two boss encounters, but technically 4 bosses. The first fight in the wing has you facing the three Blood Princes, all of which you have fought previously. The second encounter is against the Blood-Queen Lana'thal. All of the fights in this wing are fairly complicated and being new do you know enough to survive? Byron "Messiah" Mudry guides you through the basics of both of the encounters.

The Blood Prince Council is a fight against the various Blood Princes that you have faced and defeated earlier in the expansion.  The three are: Keleseth from Utgarde Keep, Taldaram from Ahn’kahet, and Valanar from Naxxanar.  Here however you must fight all three at once since they are now resurrected as undead minions of the Lich King.

You can find all the information in our Guide to Ice Crown Citadel - Crimson Halls.