Please be advised that we have produced 78 episodes of Sonic X.
However, we do not have any immediate plan to produce episode #79 and over.
Therefore the episode 79 and over of Sonic X does not exist as of today.

With regard to „more than 78 episodes“ at our site,
this is simply typo and we will fix it to „78 episodes“ accordingly.

In addition, I checked Polish site below and, according to automatic
translation,
the story depicted here seems to be related to #53-78.
http://www.telemagazyn.pl/program/3459816044.html

Therefore I assume the number „79“ here is a typo also.

Thank you for your attention.
Best regards,