These cards have not been legal in Commander for a long time (originally being banned between 2005 and 2009), and a lot has changed in both Magic and Commander since
It could be a restriction on card names, artists, art elements, flavour, or any other number of things, but the point is that the deck is built around that quirk
This was met with severe backlash since it seemed that some may have used programs to generate their work rather than create it from scratch like the rest of the entrants
These custom cards allow fans to bring their favorite characters from movies, TV series, and even other games into the world of MTG, often with stunning and imaginative artwork
It can act as a mild deterrent for removal, especially with such a low re-equip cost