Complex sentence: Typically, other competitions of varying degrees of seriousness are also run like the Scrap Demon competition which supplies modellers with plastic sprues and are expected to make a model based on the category given.
Split into simpler sentences: Typically, other competitions of varying degrees of seriousness are also run such as the Scrap Demon competition. Competitors in this event are supplied with plastic sprues and are expected to make a model based on a category given.