 The Liberty Legion was initially assembled by Bucky to rescue the Invaders brainwashed by the Red Skull.With the Legion, Jack Frost battled Namor the Sub-Mariner and the original Human Torch, and protected bystanders from shrapnel with an ice umbrella.Jack Frost was seen again in a 1991 issue of "Captain America", where it was explained that he'd sacrificed himself by melding with a powerful Arctic "ice-worm" monster, in order to neutralize it and keep it from savaging innocent people.