Board Thread:Questions and Answers/@comment-14902757-20140715194537/@comment-5780397-20150331173458

1) Nope, on that occasion he wasn't using En... first because you can't use En & Ren, as both involve emitting your aura, only one keeps it close to your body and the other spreads it around. Also, when he used En to catch Gon, you could see his aura take a spherical shape and expand, while with Phinks, it merely flowed as it usually does when a character uses Ren. Besides, En leaves your body unguarded when compared to Ren, and Phinks was already close enough to be reacged by Nobunaga's sword, so it would have been too dangerous (and also pointless) to activate it.

3) Killua would have probably developed the same Hatsu later on, but I don't think Gon would have done the same. He developed the concept behind his ability when Biscuit told him the rumor on rock-paper-scissors being born to replace martial arts, and each technique requires a category that he trained in under Biscuit. Without her, it wouldn't have been possible.