Cursed Blizzards is the fourth stage in Body and Soul.
The stage makes you face an Elder Sloth at the start. After a while, a normal Sloth will spawn. Oh, and be aware: If you don't defeat the stage fast enough, you will be faced with a flood of Elder Sloths(20), essentially guaranteeing that you lose the level.
You can bring cheap units with good DPS. Examples include Dancing Flasher, Crazed Whale, and Jamiera. Spam them until the Elder Sloth dies. As soon as he dies, use Awakened Bahamut after the normal sloth attacks. Be warned; the normal sloth 1-shots Bahamut.
Another option is to kill the massive horde of Elder Sloths using long-ranged, anti-Alien Ubers (such as Megaphrodite), and tanky units (such as Metal Cat or Frosty Kai). If you can stall for long enough, using meatshields, tanky units, or what have you, you can eventually kill all the Elder Sloths and win the stage via brute force.