I watched the anime and personally liked it a lot, but to be honest I couldn't remember every detail about Lancer's costume right on top of my head. I don't think someone would immediately know all the details of the costume just by mentioning of the name. In order to do that, one would need to intentionally memorize the costume when reading the manga or watching the anime, but then commissioners would probably have better things to do than to remember every costume they see. You wouldn't want a commissioner to make the costume from memory either, even if he or she is very familiar with the character.
Even if a commissioner knows the character well, you still want to provide reference pictures to indicate the specific costume for the character. And depending on your source of reference picture, details may vary. Without a reference picture, you may end up getting something slightly different than you expected, the color may be off etc.
I'm not trying to be rude, but I just want to let you what could possible happen. It is your decision but I'm just giving my advice.
Costume Storefeel free to commission
Nikon D7000+35mm F/1.8