This is Melkor when he was prisoner in the Halls of Mandos (painting inspired to the Black Book of Arda)
Known in English as The Black Book of Arda, Black Silmarillion or The Chronicles of Defeated, is a novel published in Russia by Vasilyeva N. and Nekrasova N. around 1992, based on JRR Tolkien's Silmarillion. According to the book by N.Vasilyeva and N.Nekrasova, the Vala Melkor was not originally the Great Enemy of Middle-earth, but a wise teacher and a martyr, while the Creator Eru Ilķvatar and the Valar are represented as tyrants without remorse.
In Arda, Melkor tried to act in accordance with his own thinking, but this was against the will of the Creator.
Original characters by J.R.R. Tolkien