I've seen worst, a man being cut into pieces by cartels.
I can't paste it here, that site liveleak.com has..
a human decapitation
throat slit..
penis amputation ..
beheading
it's right on that site..

I don't understand why they do it(this video you posted), for their belief?? 

there is another japanese version, this guy kills himself but stabbing knife right into his abdominal, forcing it in to his heart, screwing it while can and dying painfully..
Later I learned it's some traditional samurai thing, dying with dignity or something like that..

I would never understand these things..