Original sentence: He has been attacked - sometimes viciously and mostly by some ethnic Ibos of southeastern Nigerian origin - for upstaging a then more nationally prominent political figure, Nnamdi Azikiwe (an Ibo from the Eastern Region), in the contest to control the West, Awolowo's home region, and for what such crusaders have alleged to be his hard-line stance against the secessionist Ibos of the Eastern Region in the Civil War
Edited sentence: He has been attacked - sometimes viciously and mostly by some self-centred ethnic Ibos of southeastern Nigerian origin - for upstaging a then more nationally prominent political figure, Nnamdi Azikiwe (an Ibo from the Eastern Region), in the contest to control the West, Awolowo's home region, and for what such crusaders have alleged to be his hard-line stance against the secessionist Ibos of the Eastern Region in the Civil War