I recall reading of a prediction/prophecy that
when Sharon dies, all ‘hell’ will break loose.
I didn't read any prophecy about him and indeed forgot he was still among the living, and I don't get anything definite, just that there's something significant about it. Like he (and Israel) are being chastised for giving up Gaza and other concessions.
From 2006:
http://yeranenyaakov.blogspot.com/2006/03/kabbalists-weigh-in-on-elections-and.html
...As previously mentioned, many Kabbalists have said that Ariel Sharon would be the last Prime Minister before the Mashiah. R’ Nir Ben Artzi is one of them, but he adds that there may be a rotation via some National Unity government, but there won’t be a leader that will compare to Sharon’s power until Mashiah...