If I reveal multiple Nocturnes, can I play more than one? What if all 3 of the cards I look at for Stacked Deck are Nocturnes and I play all of them?

Yes, you can play more than one Nocturne at a time this way. If there aren’t any eligible cards left for the original effect you were resolving, any further instructions will be ignored. So if you reveal Stacked Deck, see 3 Nocturnes, and opt to banish and play all of them, you won’t put any cards into your hand, nor will you recycle any cards. You will, however, have 3 Nocturnes.