Complex sentence: While dragged Mio back to Tube, its Doggler aided Baraba in attacking the surface until its other half arrived to rejoin it when the Maskmen arrive to stop Tube's initial invasion.
Split into simpler sentences: While dragged Mio back to Tube, its Doggler half aided Baraba in attacking the surface. Its other half arrives to rejoin it when the Maskmen try to stop Tube's initial invasion.