See the similarities between these two.

And him.

If you are not aware about the person in the picture above here it is from Wikipedia. 

Idi Amin Dada Oumee (c.1925^[1] – 16 August 2003), commonly known as Idi Amin, was a Ugandan military dictator and the President of Uganda from 1971 to 1979. Amin joined the British colonial regiment, the King's African Rifles, in 1946, and advanced to the rank of Major General and Commander of the Ugandan Army. He took power in a military coup in January 1971, deposing Milton Obote. His rule was characterised by human rights abuses, political repression, ethnic persecution, extrajudicial killings and the expulsion of Asians from Uganda. The number of people killed as a result of his regime is unknown; estimates from international observers and human rights groups range from 100,000^[2] to 500,000.

From 1977 to 1979, Amin titled himself as "His Excellency, President for Life, Field Marshal Al Hadji Doctor^[3] Idi Amin Dada, VC,^[4] DSO, MC, Conqueror of the British Empire."^[5] In 1975–1976, Amin became the Chairman of the Organization of African Unity, a pan-Africanist group designed to promote solidarity of the African states.^[6] During the 1977–1979 period, Uganda was appointed to the United Nations Commission on Human Rights.^[7]

Dissent within Uganda, and Amin's attempt to annex the Kagera province of Tanzania in 1978, led to the Uganda-Tanzania War and the fall of his regime in 1979. Amin fled to Libya, before moving to Saudi Arabia in 1981, where he died in 2003.

Next difference: Idi Amin ruled by army coup while Prachanda was an elected prime minister.

One more: Idi Amin ruled over there by the blessing from America while Prachanda had to quit because of the blessing bestewed upon other parties from foreign forces including America. (Don't you guys think that foreign interference is too much in Nepali internal affairs??)

However, both believed/believe in bullet, not at all or that much in ballot and were/aspire to be dictator.

One more Tyrant...