During World War Three genetic experiments were carried out to create mutants with powers. These genes have carried down the generations and result in those unfortunate enough to manifest powers under the name of "witch".
Abel had apparently gone on "rampages" in Krusnik form before. The fact Tres recognized this terminology implies it's code for Abel needing to feed on vampires without interruption.
Abel sees his younger self in the girl, telling her that being angry at the world wouldn't do her any good.
Tres is an android. Which is why everything he says sounds textbook and terse.
The poor girl cannot have skin contact with any living being; just that will induce a psychic attack that makes the victim experience their worst memory. This drove the vampires who first captured her into a murder-suicide.