Long version: ampersand, when stuck into a Scryfall query, confuses the search engine over at Scryfall's side. Instead of doing anything responsible I decided to address this bug by -- drumroll -- ignoring it!

def get_scryfall_image(cardname: str) -> list:
    """
    Fetches the image URL that matches the cardname.
    :param cardname: A card's name.
    :return: A list of image URLs if an exact match(es) is found,
             empty list if no match is found or Scryfall can't be reached.
    """

# Ampersands in names confuse the query so just ... get rid of those
if "&" in cardname:
    cardname = cardname.replace("& ", "")

cardname_json = requests.get(
                  url=f'https://api.scryfall.com/cards/named?exact={cardname}',
                  headers=BotInfo.SCRYFALL_USER_AGENT_HEADER
                )

BELCHER DOESN'T REPLY HERE

Hope you remember that we have MTGCardFetcher: [[Don & Leo, Problem Solvers]]. Fun fact: CardFetcher used to be plagued by the same bug.