Is Hopeless Nightmare legal in Standard, Modern, and Commander?

Hopeless Nightmare is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic. It is banned in: Standard.

Hopeless Nightmare

Q: What type of card is Hopeless Nightmare?

Hopeless Nightmare is an Enchantment. Its oracle text reads: "When this enchantment enters, each opponent discards a card and loses 2 life. When this enchantment is put into a graveyard from the battlefield, scry 2. {2}{B}: Sacrifice this enchantment."