In a rare case of justified use of a Desert Eagle, the mercenary Bondo wields two of these .50AE handguns against Lucy (One is kept as a backup weapon). While her vectors can block most handgun rounds, both high-velocity rifle rounds and heavier handgun rounds (such as the .50 Action Express) can pass through her vectors, making this normally ludicrous weapon choice perfectly reasonable.
Both Japanese S.A.T officers and security guards inside the Diclonius research facility use H&K MP5-A4 sub-machine guns. All have a Safe/Semi/Burst/Auto selectors, and a few have dual magazine clamps. This is by far most seen weapon in the anime.
The borderline psychopathic Bondo uses a H&K MP5-A4 outfitted with a M203 during his initial hunt for the escaped Diclonius. Disappointingly, he only uses the grenade launcher once.
When one of the Diclonius escapes into the hallways of the research facility, Professor Kakazawa uses a FAMAS G2 to stop her. The Diclonius' vectors are capable of stopping most bullets (such as the 9mm Parabellum used in the guards' MP5s) but cannot stop higher velocity rounds (such as the 5.56 NATO used by the FAMAS) if they are not distinctly aware of the threat.
At the 2004 years the OutBack company create the fighting game, named Elfen Lied Fight Game. In this game a few characters used the firearm. Nyu use the MAC-10.
