Modified Humans (Kor. 개조인간들) are humans who were experimented on, usually by organizations like the Union or KSA, in order to gain more power. Successful "experiments" are usually much more powerful and biologically stable than the failed experiments; failed experiments are often disposed of, or die due to genetic instability. Failed experiments are usually the first human beings that were tested on; thus, the technology used on them isn't as advanced as the ones used on the later, more successful experiments. However, even the weakest modified humans are shown to be much more powerful than a normal human being. Powerful modified humans are able to completely transform their bodies at will, which increases their powers even further, in addition to granting new ones. Some of them are also trained to use a specific weapon to aid their overall combat proficiency.