Chinese to English translation for character in the center?

I don't know of a character that looks like that. I think it might be an incorrectly written version of 希 "xi1", which can mean "hope" but also can mean "rare" or "strange".

乾、坤、震、巽、坎、離、艮、兌等八個卦象，
天、地、雷、風、水、火、山、澤等八個自然現象
健、順、動、入、陷〈險〉、附〈麗〉、止、悅等八個卦德。
八卦鏡自古以來就是震懾邪魅的化煞物品與吉祥納福之物，…，主要作用是化煞與納福的功能。
It’s a Feng Shiu (Chinese pronunciation: Ba Gua) mirror, has been using by Taoists or some people who believe it since long time ago. It’s boasted to have functions (I personally see it as superstitious behavior) to avoid (expel) bad luck (demon) and invite good luck (fortune). And it is usually hung on the outdoor wall of a house.
Said by the above Chinese writing, each word of the eight Chinese word represents a natural element.
Among the 8 Chinese words which rounds a circle on the mirror, at least one word, is seldom used in normal writing or speaking.
As to the middle word of the mirror, It’s another/old way writing of “殺”, but we don’t use it in normal writing.
在道教中，法式匭儀裡面用的劍主要有四種，一為桃木劍、二為柳木劍、三為金錢劍（即銅劍）、四為殺生劍（一般以七星劍代替）；桃木劍屬陽、柳木劍屬陰，金錢劍是取古錢之銅為媒，殺生劍則是取其煞氣，這四把劍之分別在於執行之法式匭儀不同而已，基本上分別在於法，而不是在於器。
Oh, I can’t understand the true meaning of all the 8 words on the peripheral area of Ba Gua mirror. But I can guess why put a word with a meaning of “kill” on the middle of it. Because when a Taoist priest is performing magic power, normally a sword is needed, said by the above copied writing. And because Taoist magic powers have lasting for thousands years, so an old word with a meaning of “kill” is still on the middle of Ba Gua mirror aimed to kill the demon.
Oh, I’m an English learner, my writing might be poor.