In the long history of human warfare, no soldier has ever been as well trained or as well equipped as the Mobile Infantry trooper. Armed with the most sophisticated weaponry ever developed and encased in the bulwark of powered armour, Mobile Infantry troopers are intended to stride like gods across the battlefield.
Still, at their core, these troopers are only humans. For all its qualities, the human race is a physically frail form of life – at least when compared to the bugs. Despite the best equipment and training SICON can provide, there are some places troopers cannot go, not without absorbing immense casualties. For these situations, SICON has created the CHAS unit.