Resistance: Fall of Man
The Backlash Grenade, as the name implies was designed specifically to fight back against the Chimeran army. The Grenade itself does no actual damage, but the effects it causes are nothing short of remarkable and they definitely helped turn the tide in the war.
When the grenade lands, it creates a circular shield which disperses from the centre of where the grenade landed. What makes the shield unique, is that it a) harms Chimera and b) is impenetrable by Chimeran weaponry. This means the weapon can be used in various was, as either a shield, or an offensive weapon.
Obtained: The Backlash Grenade is acquired during the second playthrough in Manchester - "The Cathedral". Just before the first checkpoint in the level is obtained, the Backlash Grenades can be found inside a kitchen.
Tip: When faced with Leapers and Crawlers, throwing a Backlash Grenade in their path will cause their demise, since they will try to run through it and in the process, injure themselves.
Tip: If you're being attacked by multiple Hybrids and/or Steelheads, there are two options. Either throw a Backlash Grenade at your feet and watch them die from their own rebounding bullets, or throw a Backlash Grenade around them, and watch them rip themselves apart.