I think you are too locked in the names of the sets. Look at what a set does and how it depicts it, rather than how it's named. Necromancy summons zombies, grave knights, a lich, ghosts, and has dark blasts, but there aren't any specific tells that the set must be magic, (no magic circles, runes, etc). Demon summon, as I previously mentioned, is a bit harder to write off. All you know about robots is that you summon robots - there is nothing to indicate how you created/summoned or control them. There's no indication as to how they are powered, or if their internals are also, in fact, artificial. Radiation likewise lacks any specific indicators as to its origins/source. Guns, especially with certain weapon models, can be explained as part of pretty much any origin.