BOSS: ODIN

As in the game, this boss would have two separate phases.
But, in this case, the first one would take place inside Odin's Great Lodge. Being the core area the main hall, but would often move from one room to another, destroying furniture, walls and roofs in their wake. Until leaving it practically in ruins.

Upon the player depletes the health bar of this first phase entirely, it is when Odin manages to paralyze both protagonists with his magic. And while he is giving his villain speech, this time what interrupts him is to see Gná's head rolling at his feet. And immediately after, he begins to choke and Freya appears holding the rope. Then follows the identical cutscene to the video game, in which the former couple catches up.

Until Odin throws the raven Huginn to the vanir to snatch the rope, when a badly injured but still alive Vidar will conveniently appear from the top of the rubble to rescue his father, hitting and collapsing the ground at everyone's feet.

This second and final phase of the fight would take place in Odin's basement studio, just like in the game. The same opening cutscene occurs in which Atreus gets rid of the mask and the All-Father is enraged by it.

Note: Regarding the mask and the rift, the same as with Thor's death: it doesn't satisfy me but remains unchanged.
It seems to have been all for nothing in this issue, and it doesn't work as more than a "MacGuffin". Maybe I would have given it another purpose like making Odin or Atreus more powerful for a more bombastic final fight... although I'm not convinced either because I think it should involve something more transcendent. That said, I'll leave it as it is for the same reason as Thor's fading: I don't fully understand the narrative intentionality of the object.

The big difference in this boss phase is the presence of Vidar, who would be mostly keeping Atreus and Freya entertained, while Kratos has an one-on-one combat with Odin (thus solving the 3 vs. 1 fighting of the game that, personally, is so uneven to me). Although on occasion, the fights would intertwine, exchanging blows with each other indistinctly. Which would also make the middle cutscenes of combat transitions to be somewhat different for the most part.

 Note: During the second phase is when Odin conjures the elemental shields, only vulnerable by attacking with the right Kratos weapon according to the appropriate color. So, he would also protect himself with a shield (probably yellow) that could not be weakened by any of the weapons in the previous arsenal, but exclusively using Mjölnir.

Finally, once the boss is finished, the next scene begins with Vidar being totally tied up by Freya's roots and ends with a final combined beating by the three heroes on Odin in a similar way to the original material.

The following cutscene is unchanged from the original. Atreus ends up introducing Odin's soul in one of the marbles and later Sindri appears suddenly to destroy it, ending definitively with the All-Father.

Right after that Vidar manages to get rid of the roots that held him prisoner and, without a single sign of violence, he slowly approaches the corpse of his father. He takes him gently in his arms trying to pronounce sounds, then walks away from there while he can be heard murmuring trying to find the words "F-fa-failed.... Y-you... I-I f-failed y-you.... F-father", breaking his vow of silence.

Note about an alternative boss phase: I admit that the epic and the scale in this final battle with the father of the Norse gods is missing to me, and as I said before, I considered a third phase in which Odin would manipulate the remains of Ymir's corpse (one of the possibilities is that he could do it with the power of the rift, seeing with the mask through it). Turning him into a more challenging, fearsome and imposing opponent (very similar to the final boss of the previous game, when Freya uses Thamur's body to her advantage).
But... maybe it was already too much considering what is yet to come?

Kratos, Atreus and Freya emerge from the underground zone briefly climbing the crumbled walls, while strong tremors shake the earth.

In the distance, staggering through the dust, an exhausted Freyr can be seen at his limit. He warns you: "It's Ragnarök... he's here...! With each passing moment he grows more powerful, he has begun to open rifts between kingdoms... At this rate, he could end up annihilating them all."