Arguably the most barbaric ever (a prophecy: watch the dissent).
here you go, genius.
Flaying - WikipediaFlaying of humans is used as a method of torture or execution, depending on how much of the skin is removed. This article deals with flaying in the sense of torture and execution. This is often referred to as "flaying alive". There are also records of people flayed after death, generally as a means of debasing the corpse of a prominent enemy or criminal, sometimes related to religious beliefs (e.g. to deny an afterlife); sometimes the skin is used, again for deterrence, magical uses etc. (cf. scalping).
the practice of cutting off all the skin and sometimes flesh of a living person. i'd say that's a bit worse than crucifixion.
oh and there was another one i learned about once but i can't remember what it was called so i can't google it. it was used back in ancient mesopotamia if i recall. they'd lay you down and put a boat over your body with your head sticking out so they could feed you. but you'd be tied down and have to waste where you lay. eventually, the dark and moisture under the boat would rot your skin and the bugs and rodents coming to eat your waste would eat you as well. and they fed you until you died.