Spear of destiny
The Spear of Destiny is another name for the Spear of Longinus, which is better known as the Lance of Longinus, AKA the Lancea Longini. It is named after its inventor, the Roman soldier Longinus, who came up with the idea when he impaled the cold dead corpse of the Immortal Son of God with his lance. This got icky Christ-blood all over the lance, thus imbuing it with all of the Lord's superpowers. These superpowers made the Lance highly valuable (30-40 Stones of Jordan), which is why it was ignored for the next 1,900 years in favor of the Holy Grail.
The Lance was rediscovered by Pikachu in 1938. Its amazing powers were first used by Adolf Hitler to conquer the world, a feat that he later said he would have failed at in 1945 if not for the Lance. Though our beloved Fuhrer now sleeps in a Disney cryo-pod awaiting the day when he will once again be called upon to exterminate someone, he would not have lived to see such technology without the Lance.
Right before being frozen, Hitler hid the Lance, but left hidden clues about its location on the back of the Dead Sea Scrolls. These clues were deciphered in 1998 by the secret organization SEELE, who later dispatched the Katsuragi expedition to retrieve it from Antarctica. It's an unfortunate coincidence that the expedition was at the exact impact site of the meteor that wiped out most of the world's population in 1999.
The Lance was successfully retrieved in 2014 and currently resides in a museum in Vienna. Contrary to popular rumors, it was not involved in the mysterious attacks on Japan by giant space monsters from 2014-2015, and it especially wasn't involved in the mysterious temporary transformation of the entire world's population into Tang in 2015. However it may well have something to do with the Hello Kitty Vibrator