Therefore...
(originally それ故に)Fortunately, no problem with him has occurred, too.
(originally 幸い、そちらも特に問題は発生してないよ)Just before Nito showed up, Iwakasa already had witnessed the presence of something that transcends the physical world.
(originally にとが姿を現す直前に、岩笠はすでに世の理を超越した存在を目の当たりにしている)Nito's figure, who disappeared in front of him, surely...
(originally 目の前で姿を消したにとのことも、きっと)Probably it is... Because of that girl.
(originally 恐らくそれは。。。あの彼女がいたからだ)...would be also recognized as a kind of the same evil spirit.
(originally 同じ物の怪の類として認識したいとだろう)