TFT Items Questions

So with TFT Items and certain champions I wonder if items such as Jeweled Gauntlet Work on Champs that have abilities that are not cut in stone. For example, Kassadin with Jeweled Gauntlet. If so, does Hurricane also work on his ability passive?. I know it works for vayne, but for some reason it doesn't work on Twisted Fate. Does Hurricane's passive only hit champs that's not in Graves' Hitbox? So if he has firecannon and hits 4 champs, does Hurricane target 2 more outside of that. I have so many questions. Does Deathcap extend the duration of abilities not attack based like shen and braum? I NEED ANSWERS.