Complex sentence: At that time, it was a very dark cartoon concerning heavy metal subcultures, but Myhre has turned it brighter with the years, although she still frequently publishes strips about serious issues, especially in the larger Saturday panels.
Split into simpler sentences: At that time, it was a very dark cartoon concerning heavy metal subcultures. Over the years Myhre has turned it brighter, though she still frequently publishes strips about serious issues, especially in the larger Saturday panels.