The Holy Lance or Spear of Destiny was believed to make it's bearer invincible. It was not in Himmler's safe however, as General Patton captured the Spear that the Third Reich possessed when Nuremberg fell after heavy bombing.
Hitler and The Spear of Destiny
As for atomic bombs or plans for them, fatman and littleboy (according to a so-called "official" story) would not have been of German origin because German physicists claim to have purposely held up the program, pointing them toward nuclear reactors instead of nuclear bombs. After interviews given after the war however, it was believed that they never possessed the proper understanding of how an atomic bomb would work to ever have a chance to build one.
Once again though, this story seems to follow "official" doctrine for the WWII atomic programs' histories.
This would however seem to preclude Himmler's safe being a storage place for nuclear designs.
Of Physics, Friendship and Nazi Germany's Atomic Bomb Efforts
