Cristal bomber are heavy armored Sombra soldier that specialise in explosives.

They are equiped with a grenade launcher on their right legs they use for destroying ennemy positions and fighting at long range and a flame thrower mounted on their left leg for mid range fighting and crowd control.

Their armor is extremely thick and can take magic blasts, allowing them to walk under heavy fire and wreaking havoc in ennemy ranks. Their armor may be very sturdy but it’s also extremely heavy, as a result their back is left unprotected to reduce its weight (and they are not supposed to retreat anyway). The weight of their armor becomes an advantage at close range as even a single punch from them will send any normal soldier flying.

The crystal bombers played a major role in taking down the changeling kingdom as they were the only one who could fight inside the hive. Sombra and some of his best magic users attacked the changeling hive and let themselves be captured by Chrysalis who took them to her throne room then, Sombra then sent a signal to a group of crystal bombers who stormed through the hive, closed in to his position and destroyed Chrysalis throne, dooming the changelings, as now, Sombra and his soldiers could unleash their full power.

Phew, this took longuer than what I expected, I had to redraw this four times but I think it ended up good.