On earth, at least before Sui Xiong time traveled here, in addition to the mysterious killing weapon in the legends, the most horrible troop was self-detonating soldiers.
They didn't need gorgeous equipment, long-term training or strong back-up support. They only needed to encircle strong explosives on their body or put several kilograms of TNT in a car. Then, they only needed to get as close as possible to the enemies and ignite the explosives.
Boom!