Intense psychological turmoil - and encounters

[Sirius]

Sundance Ceremonies

It was noted that only the most committed individuals performs this ceremony. 

Right so what have we got here? Channeling a powerful entity, the sun no less.

erected a dance structure with a central pole that symbolized a connection to the divine, as embodied by the sun.

I can dig this.

 did so in fulfillment of a vow or as a way of seeking spiritual power or insight. 

Yikes!

When practiced, self-mortification was generally accomplished through piercing: mentors or ritual leaders inserted two or more slim skewers or piercing needles through a small fold of the supplicant’s skin on the upper chest or upper back; the mentor then used long leather thongs to tie a heavy object such as a buffalo skull to the skewers. A dancer would drag the object along the ground until he succumbed to exhaustion or his skin tore free.

Among some tribes the thongs were tied to the centre pole, and the supplicant either hung from or pulled on them until free.

https://www.britannica.com/topic/Sun-Dance