One of my favorite things in the Metropolitan Museum here in New York is this 14th century Japanese Parinirvana showing Buddha dying his last death and entering Nirvana. The Museum very rarely displays it. It's not on display now, and I haven't seen it in the original in years. But, thanks to the magic of digital scanning and the internet age, the Museum has made a high definition reproduction available.
Gautama Buddha died in a forest by the side of the road at the age of about 80 around the year 400 BCE surrounded by his grieving disciples; and according to later legends, the gods, demigods, and creatures of the forest.
The artist contrasts the majestic serenity of the Buddha as he dies his last death with the grieving that surrounds him. The artist wants us to sympathize with the grieving mourners, but also pokes a certain gentle fun at them. I love the grieving animals in this picture, especially the hysterically grief stricken elephant on his back kicking up his legs in a tantrum of protest.
There are a lot of beautiful passages in this painting, especially the forest and the night sky.
I'm afraid that I don't know my Buddhist iconography well enough to tell you who all the Bodhisattvas, Arhats, gods, demi-gods, etc. are.
This painting has that sense of sympathy and emotional range that is what's best about Buddhist art from the violent dictatorial Kamakura era of Japan.