You use unusually to emphasize that someone or something has more of a particular quality than is usual.
He was an unusually complex man.
他是个异常复杂的人。
You can use unusually to suggest that something is not what normally happens.
Unusually, for a Japanese politician, he's a fluent English speaker.
不同寻常的是,作为一位日本政府官员,他能讲一口流利的英语。