The climatic Fontaine archon quest part 5 was such a information dump that you might have missed a few things. So allow me to explain how this chapter changes the game. Starting with what exactly the all devouring narwhal is, why was Focalors death so important and why the Heavenly Principles are closer than ever to making an appearance.

Massive spoilers for "Masquerade of The Guilty" and some of the new world quests surrounding the Narzissenkreuz Ordo.

____Chapters___

0:00 Intro
0:52 What Is The All Devouring Narwhal
1:21 Tartaglia's Past History With The Whale
3:08 The History of The Primordial Sea
5:23 Where is The Primordial Sea
6:50 Fontaine's Prophecy
9:26 Teyvat Has Changed