Complex sentence: In time, the rogue Faltines led Olnar to shatter the barrier between his dimension and that of the Mindless Ones, a horde of soulless brutes that exist simply to destroy anything that lies in their path.
Split into simpler sentences: In time, the rogue Faltines led Olnar to shatter the barrier between his dimension and that of the Mindless Ones. The Mindless Ones were a horde of soulless brutes that exist simply to destroy anything that lies in their path.