The ancient Sumerians were the first great empire on earth, worshipping a great elder god called "Mickey". After the empire fell, worshippers of the god went underground and continued to thrive. In the 20th century, these remnants established a global corporation called Disney, spreading worship of the god across the world through theme parks, movies, etc. This feeds the entity's power and allows it's influence to grow.
The Sumerians continue to use their ancient language for spells given to them through Mickey's power. The language's lexicon has been fully discovered and translated. However, when Sumerian is translated into other languages, such as English or Spanish, the spells simply don't work. For whatever reason, a spell must be conducted in its original language in order to be successful.
How can this be the case?