User blog comment:Patrick x hunter/some nen ability's do not work/@comment-5780397-20150918233309

As Daedalus pointed out, visualizing and training are probably the most important aspects for Conjurers, especially becaus ethe true core of their power lies in the fact that what they manifest is not just an object, but their fantasy itself: they acually ebnd reality to suit their needs, using rules and limitations. However, I thought that Kite could Conjure only weapons he had a thorough knowledge of, even though he might not have liked them.

Poison gas shouldn't be a Transmutation ability. It might be a very complex Conjuration ability, or a moderately complex Manipulation ability (which would probably include Cnjuration, too). That's because Transmuters do not create objects, but merely alter the properties of their Nen: Killua's electricity is not real, it probably lacks some of the characteristics that real electricity has; for example, it might not be influenced by water. It is not a flow of electrons, just "electrocuting aura". Keeping this in mind, I don't think you could turn your aura in poison gas, although maybe you could expand your aura using Emission or En (which would be extremely hard and extremely tiring), and then make it, let's say, explode once it comes in contact with the opponent, though they will never be able to breathe it in, unless you first Conjure a smoke and infuse its particles with explosive/corrosive aura.

On the other hand, it should be possible for a Transmuter to give their aura into "cold"; however, if you want to create ice where there is no moisture, you'd be using Conjuration; and if you were freezing pre-existing water without lowering its temperature (acting on its density), that would be Manipulation. Plus, to create enough ice strong enough to damage a Nen user, you'd really need some terribly risky Vow.