I found them on forum.df2.ru. I already found the last two files, but I lost the Inferno mod (new Windows installation). I used to have it installed. Basically, it features new devils and higher-tier ones (Archdevils and Barons) from 5 heroes, and the Ifrits have been replaced with Rakshasas (something like regular devils, but they move around like a whirlwind). It weighs 1.1-1.8 megabytes. It's called inferno_mod (it's either in a RAR or ZIP archive on that site, but I can't get an activation email from it, meaning I can't fully register, and regular users are prohibited from searching the forum).