Desperate Acts of Yoku and Bosmer and the Unintended Consequences

Edited out the bit about the Yoku. It wasn't really worth discussion.

The Wild Hunt

So far as I understand, the Bosmer are somewhat bashful when it comes to the Wild Hunt. It's not something they're particularly proud of, and seem to enact it either sparingly or out of public sight (or both?). Like the Twenty Seven Snake Folk Slaughter and the Pankratosword, the Wild Hunt is both an incredibly effective and brutal ritual. As probably most of you are aware, the Wild Hunt results in the Bosmer's uncontrollable shape-shifting into every beast and monster imaginable (and some unimaginable). Anything standing in the path of the Wild Hunt is slaughtered and devoured. When nothing is left to kill, the members turn on one another, devouring and killing until...?? Everyone is dead? The effects wear off and everyone walks home embarrassed and refuses to make eye contact?

The first documented Wild Hunt occurred in 1E 369, and had the intended effect of assassinating Skyrim's High King Borgas. Borgas was a staunch supporter of the brutal and fashionably boring Alessian Order. He was also the leader of the First Nordic Empire, which was composed of Morrowind, Cyrodiil, High Rock, and of course, Skyrim. As related in the Civil War quest line in "Skyrim," he was also the last ruler in Skyrim to wear the Jagged Crown.

At the time of his assassination, he was travelling on official Imperial/Alessian business to Cyrodiil, the business of urging joint warfare against the Bosmer. Given the might of the First Nordic Empire, the Bosmer were understandably concerned about whether they could withstand the weight of such an onslaught. They could not, and it was imperative to the survival of the Bosmer people that such a meeting never take place, and preferably, that Borgas never return home. Thus, the Wild Hunt was initiated, and succeeded (presumably) beyond their expectations.

Borgas was slaughtered. His remains were interred to a tomb in Skyrim, resting with him was the Jagged Crown. The First Nordic Empire was shattered, with all governed provinces breaking away from Skyrim. Skyrim itself was plunged into civil war.

An unintended side effect of the Wild Hunt: Skyrim's method of governing transformed radically from then forward. The loss of the Jagged Crown was more than a symbolic loss. Borgas, and all rulers who wore the Jagged Crown, ruled by sheer might and power, and were, for the most part, absolute in their power. Coinciding with the loss of the Jagged Crown, the idea of the Moot was introduced at this time. The Moot removed the autonomous and absolute power vested in the High King, and made it possible to (probably?) peacefully remove a High King from power, should he displease the Jarls or break from tradition in a way that is unbefitting to a leader of Skyrim.

Specifically, if a High King refuses a challenge, he is no longer considered fit to rule. Jarl Ulfric used this ancient and obscure rule as grounds to challenge and subsequently assassinate High King Torygg, unintentionally strengthening the Aldmeri Dominion's position against Men in general, and also accidentally fulfilling an ancient prophecy that would usher in a new age of dragons/apocalypse scare/potential kalpa reset.

Another unintended side-effect: The establishment of the Colovian Estate. Breaking away from the First Nordic Empire allowed the Colovians to assert their independence, leading to the creation of the Colovian Estate, which in turn lead to the eventual demise of the Alessian Order, and the formation of the Empire as we know it today.

So...all that aside, what other brutal acts of desperation have the races of Tamriel enacted to preserve themselves or otherwise perpetrate a cause, and what were the unintended consequences?