A very real, truthful reason why Gustave invented the Lumina converter.

In the beginning, there were very little use of stuff like Pictos or Color of luminas. These things just collected along the streets of Lumiere.

People in Lumiere keep on picking these things and always says "Good stuff" everytime they pick one. But then they throw it back in the streets for the next person to pick since it serve no purpose at the time. Lumiere is very noisy with all the people saying "Good Stuff", "Good stuff", "Good stuff" all the time.

4 years ago, all these "good stuff" starts to sound like "Gustave" to a certain person with the same name. He keeps on hearing "Gustave", "Gustave", "Gustave" like it's calling him every single moment. Until one day... He snapped.

"ALRIGHT ALRIGHT, I GET IT ALREADY, STOP CALLING MY NAME!!!" Gustave then invented out of desparation, a way to convert these pictos and the colors of lumina into something useful, thus he eventually invented the lumina converter and then the streets of Lumiere were finally rid of these collectible trinkets.

(Thanks to u/Reddit__Please__Help for the question "What did people do with pictos and color of lumina before the lumina converter was invented", and telling me to post my answer here)