In Record of Ragnarok, Siegfried did not seem to commit any serious crimes that made him be imprisoned in Tartarus. So what is the reason why Siegfried was detained by Odin. Why did Odin take so much effort to lock this god?
1. According to the Buddha's information, Siegfried was locked up for allegations of stealing Gram magic swords

This cause has been discovered by the Buddha during his research. From what he had, it was thought that Siegfried stole Gram magic sword and murdered the Fire Dragon Fafnir. This action is considered a crime that makes him be imprisoned in Tartarus, as a preventive measure against the rebellion against heaven and even taking the lives of the gods.
But in fact, Gram Sword itself is Odin's sacred treasure, the original god is currently the head of the Nordician pants, this truth is only revealed in the latest chapter.
In addition, reviewing the punishment is only for sinners, but Siegfried's crimes are not that level. Therefore, it can be said that Siegfired has been locked throughout the past time with wrong allegations.
2. Initially, Siegfried was locked by Odin because he was the original Holy

One of the prisoners mentioned Siegfried's Asian Blood
The reason Odin locked Siegfried was his own ambition. Odin discovered that Siegfried was the original Holy Saint suitable for the plan to break the Glepnir seal that was detaining the supreme original gods of other creativity, Ymir, Satan and Chaos.
So Odin locked him and did not let Brunhilde's lover die until his plan was done.
3. Siegfried's background factor is the god that makes Odin care

There are criteria for an original object that Odin needs to be able to use all the sacred treasures of the original gods. The four sacred treasures have the corresponding aspects of earth, sky, nowhere and underneath.
Odin happened to find a suitable person, Siegfried, who was both a god and a human being. So the aspects of earth and heaven have been completed.
4. To perfect the divine aspect of the original object, Odin imprisoned Siegfried in Tartarus and assigned him the Mark

Siegfried thanks to Goll for help
To complete the aspect of nowhere and underneath, Odin did something with Siegfried.
The hybrid between humans and the god was imprisoned in Tartarus, becoming the symbol of the world. In addition, Siegfried is also considered the god of deadly sin, an aspect of nowhere.
Thus, Siegfried has met the requirements of holding the power of four treasures of destruction. And the water of life is inherently the energy of humanity.
However, because of this great power, Siegfried will definitely die after breaking Glepnir's seal. And the worst is that the tyranny of the Yggdrasil pillars will start again, causing the gods to be threatened.