E.L.S also known as Echo Location Skill that uses sounds as their combat skills. It acts on the same principle that Bats or dolphins use.
E.S.L was thought to Salim by Morito when Salim lost his eyesight, but refused to leave and retire from being a Merc. It makes use of sound waves similar to dolphins and bats do. Practitioners of the skill possess incredible hearing, able to differentiate individuals from their heart rate and breathing alone. Allowing individuals with little to no Visual Acuity to not only function unimpaired in their daily life but participate in Merc Missions.
- Sound Silencing
Unexplained fully but involves being too dependent on the practitioners ears/hearing alone. One example was on Salim's mortal death; wherein he mistakenly identified a time bomb stopped beeping as having turned off, but simply continued with it's fuse; thereby exploding and killing Salim.