Board Thread:Theories and Speculation/@comment-5012682-20150620162706/@comment-5936871-20150620175720

@Omo I see, well even if Sasuke's main affinity is lightning. Due to being an Uchiha, he still inherited fire release naturally. So those two are his strongest natures. The issue with the Boruto thing though, is since we don't know Hinata's affinity, we can't use that as proof for Boruto despite them sharing the same nature I guess.