Complex sentence: Roberts rejoined his bandmates in Firefall from 1989-1992, he retired from performing due to illness; although in 2010 he returned to music and released two 4-song-EPs on iTunes and launched his website.
Split into simpler sentences: Roberts rejoined his bandmates in Firefall from 1989-1992. In 2010, he returned to music and released two 4-song-EPs on iTunes and launched his website.