Firebendrian is a xenogender and specifically a fictigender based on the show Avatar the Last Airbender (ATLA). It is a gender where one feels related to the show's firebenders, the concept of firebending in relation to the show, and/or a specific firebender character. It is not a gender simply related to fire, but to firebending, its power, aesthetics, and history. If one feels a specific connection to a firebender character from the show then they may add the name of that character to this to make something like "Azulabendrian" or "Zukobendrian", or something like "Azulagender" or "Zukogender".
If one feels more connected to the aesthetics of firebending, then they may use this as an aesthetigender, but it isn't explicitly an aesthetigender. Firebendrian may or may not also be a kingender.