Mother Lode

"Mother Lode" is a rumored treasure among Diggers said to be a giant and valuable Refractor that has enough energy to finish the energy crisis and make the wearer rich. However, it's revealed in Mega Man Legends 2 that the Mother Lode is not a treasure, but "a catastrophe" as said by Yuna (inside Matilda). It's believed she refers to the Mother Unit Sera.

The Bonne family thought they would find the Mother Lode under the surface of Kattelox Island. They were mistaken, as they actually found the resting place of Megaman Juno. However, they did find a very large Refractor in his chambers that they took with them. This was not the Mother Lode, but it was the largest refractor seen in the games.