Complex sentence: They joined the Awgwas in their fight against the Immortals and were wiped out by the Ryls who stabbed their sharp bramble-bush thorns through the Goozzle-Goblins' hearts.
Split into simpler sentences: They joined the Awgwas in their fight against the Immortals. The Goozzle-Goblins joined the Awgwas in their fight against the Immortals and were wiped out by the Ryls who stabbed their sharp bramble-bush thorns through the Goozzle-Goblins' hearts.