Complex sentence: Unfortunately the stand led to the Elites' slaughter as their out of date Mark 34 Titanium Guard Armour was useless against the humans ATB (Anti Titanium Ballistic) rounds.
Split into simpler sentences: Unfortunately the stand led to the Elites' slaughter. Their out of date Mark 34 Titanium Guard Armour was useless against the humans ATB (Anti Titanium Ballistic) rounds.