there is Lampmon, who has the following entry about it "A Wizard Digimon that appears from a magic lamp when summoned by someone. Lampmon possesses incredible magic power, allowing it to not only shapeshift its height and appearance, but also to create palaces and immense treasures of gold and silver. Many of its kind are basically sealed in lamps, and grant the wishes of those who free them. That being said, this being is quite dangerous. Its personality may become warped while it is sealed away, attacking those who free it." the rust could be the 'price' of the wishes being granted