An 'evil Santa' in a Christmas story could be a really interesting and different take on the traditional Santa Claus. Maybe this evil Santa doesn't bring presents but instead causes trouble. He could be stealing presents or scaring children instead of spreading joy. It might be a story that plays with the expectations of what Santa is supposed to be like and turns it all upside down.
The themes in 'evil santa a christmas story' can be quite complex. For example, it might explore the idea of the dark side of human nature, even in the most beloved and positive of figures like Santa. It could also touch on the idea of redemption. Maybe the evil Santa has a chance to turn back to his good self. Another theme could be the exploration of the impact of fear during a time that is usually associated with joy. An evil Santa would bring fear instead of happiness, and the story could show how people deal with this unexpected and terrifying change in the Christmas spirit.
The number of Futurama comic issues can vary. It depends on the release schedule and production decisions. You could try searching online comic forums or fan communities for more specific details.