Actually, Shinto is anything but a "death cult". However, to most it remains a mystery.
However, it must be recognized that unlike most other cultures on the planet, Japan still does not have a strong cultural prohibition on suicide. In times of bad economy, it is still not unusual to see the owners of businesses that fail kill themselves from a sense of shame because they failed. And it is still common when adults get fired. Or even among teens who fail entry into a university they wanted to go to.
Where acceptance and conformity are the norm, and failing to live up to that can lose face. And in the culture, suicide is an accepted way to regain your honor. But that is not just Shinto, that is simply their cultural viewpoint. Not unlike a rabid Islamic suicide bomber would see nothing wrong with killing themselves to take out some they see as the enemy.
In that, culturally the Japanese people are not much different, but they generally do not rush out to embrace death as a rule. There are always some fanatics, which is how the Kamikaze started in the first place. But if a battle is lost, they still believe it is better to die fighting than to surrender.
It must be remembered, this was a unique culture, that while not looking for death, also did not fear it. Where before entering battle a Samurai would take care to make sure their make-up and hair were perfect. So if they fell in battle, their head their head would look it's best when presented to the commanding general. Something continued even as the Meiji Restoration stomped out the last of the Samurai.
And even into the Showa era, the Japanese thought nothing of beheading, even though it horrified most of the rest of the world. However, I will admit that I often chuckle when I see some hipster with a douche knot, and wonder if they wear it for the same reason the Samurai wore theirs.
So the victor could easily hold their head after it was cut off for presentation. And they would be sure the person presenting it was not soiled by their blood.