First, you might want a console hack. Some console hacks have one hit kill and godmode build in, but if it doesn't download Nicdel's extension.
Next, if you want binds, use Pie Binds. You hacks will load by pressing a single button.
Then, you need the injector to inject your console hacks/ohk,god.
You can use winject, perx injector, or any others.
(google is your friend)
Once when you have your injector, open it(run as admin if vistadows 7). Go down the list and select Nicdel's ohk/god hack and your console hack.
Select vindictus.exe for injecting. For perx, you can set it as auto inject, or you can manually inject it.
Once when you are ingame, you can type god(godmode for helldemon's console) for godmode, or ohk for one hit kill. Here is a list of commands you can use. WATCH OUT FOR THE RANKINGS.