Just a few notes regarding his string abilities
Strings || A microfiber that lives within his body and allows him to control his victims like puppets. Once connected it allows control over their nervous system and sense. Giving him the ability to make them perceive to do as he pleases with them. The strings themselves are not visible to the naked eye and do not require direct contact with the person to connect to them. It is possible for a brief moment of time to fight against them but only if one has a substantial amount of will-power(note one instance where Radu breaks free for a few seconds. Enough to spare Ion his life).
These strings are capable of being burned off by a strong enough fire(likely a fire that would start to burn off skin). Otherwise once implanted they are struck until he retracts them or there is a great distance between him and the 'puppet'. While never stated in canon it seems to be capable of being used within the range of a few miles though the distance does affect the controls. To be in absolute and perfect control he would need to be somewhere within fifty-or so feet of the target.
A fun extra is that he strings can actually be sharpened and used as a weapon. To the point where it can easily cut through skin. Just as he did when he cut Ion's jugular.
Magic || And as Isaak's protege he has a few gifts of basic shadow magic. Nothing complex. If anything he might be able to make something akin to the shadow monsters that Isaak can produce and use them to move to and from places.
Technology || He is also a genius with technology. Such as understanding machines that existed during Armageddon and understanding technology that probably only the crusniks and Isaak would understand. So he might be trying to hack into things for fun.
A few permissions!
[ ] Being maimed/tortured be it physically or mentally
[ ] Being a puppet of his for a time
[ ] Tone Hacking
[ ] Misc. Anything that you might specifically want to use him for with your pup
Any questions or concerns regarding the strings are free to be asked here!