Is Mercurial Chemister legal in Standard, Modern, and Commander?

Mercurial Chemister is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

Mercurial Chemister

Q: What type of card is Mercurial Chemister?

Mercurial Chemister is a Creature — Human Wizard. Its oracle text reads: "{U}, {T}: Draw two cards. {R}, {T}, Discard a card: This creature deals damage to target creature equal to the discarded card's mana value. *What some see as "distracted" is really "fathoming the unfathomable."* Power/Toughness: 2/3"