I'd want to touch upon Elsa's path in Frozen 2 from the point of view of the Hero's Journey theory based on the works of J.Campbell on Monomyth (and I will touch a little upon Anna and Kristoff's part) A quest for a hero is divided into several steps or stages. Not all stories follow them literally, but I find that Frozen 2 up corresponded quite well with the theory.
The first step: The Call to Adventure ✔
Elsa literally receives the call that calls her to go into the unknown from her usual life and to leave the kingdom.
(Anna and Kristoff do not receive such a call, but only follow Elsa, although Kristoff's words "it feels like the future is calling" reflect the situation for all of them.
The second step: Rejecting the Call ✔
"I'm blocking out your calls"; "I've had my adventure, I don't need something new".
(Anna tried to rely on certain familiar things, not noticing that they were changing before her eyes. She didn't want to let Elsa go alone. Kristoff at first refuses to give the sledge and Sven)
Step 3: Supernatural Help ✔
The appearance of the trolls that hinted to them about the essence of what is happening with the kingdom.
Step 4: Crossing the Threshold ✔
The wall of mist that separated the ordinary realm from the Enchanted Forest. The Monoliths with the signs of the elements.
Step 5: The Belly of the Whale ✔
Elsa was able to pass through the wall, and plunged into the Forest with all its wonders and dangers. After passing the threshold, the hero often meets new people – helpers. For Elsa these were Northuldrians and Arendellians, who give her information and tips for The Journey.
Step 6: The Road of Trials ✔
"A series of tests, tasks or ordeals that the hero must undergo to begin the transformation".
Elsa fights with three spirits, showing what she is capable of. She and Anna are able to find the clues left by the parents.
(Kristoff saves the reindeers, and then Anna from the earth giants. Anna destroys the dam.)
Step 7: Meeting with the Goddess, which represents unconditional love and motherhood ✔
Snow statue of Iduna. The meeting with the memory of Iduna and Ahtohallan the Goddess.
Maybe this is Elsa's temptation to not go that far. Maybe, after finding the shipwreck, for a moment she was tempted to give up everything. Anna's attempts to stop Elsa.
Step 9: Atonement with the Father which represents the questions of power and authority ✔
Elsa learns the truth about Agnarr's past and Runeard's deeds. The question of power that Elsa faces is her royal status, which she received thanks to Agnarr and Runeard. She symbolically opposed the power of Runeard and atones for his sins.
Step 10: Apocatastasis or restoration. Revelation ✔
"When the hero dies a physical death...he or she moves beyond the pairs of opposites to a state of divine knowledge..."
Elsa gained the truth, got a mystical experience with Ahtohallan, was transformed into The Fifth Spirit and died.
(Anna, meanwhile, is coping with the consequences of the death and destroys the dam. By this she also atoned for the sins of the fathers and gained wisdom: even if all is lost just do the next right thing.)
Step 11: The Ultimate Boon ✔
The curse is broken, the Forest is liberated, Elsa has been resurrected and the castle has not washed away. Now she is completely free and in peace with herself.
And that's where the divergence with the Hero's Journey Theory begins. Elsa breaks through the limits of the Theory here, and the circle has been closed, because she has two homes.
Step 12: Refusal of Return ✴
"Having found bliss and enlightment in the other world, the hero may not want to return to the ordinary world to bestow the boon into his fellow men".
Elsa decided to stay with the Spirits and Achtohallan and did not return to the old home, because the Forest and Ahtohallan and Northuldra are the true home, that home where she had to return initially, since the time she was born. If she refused to stay here, then it would be The Refusal, because her presence in the Forest and her role as the Ruler of Nature Elements, Keeper of the Forest, Seer of Ahtohallan is that bestow of the boon into her fellow people: the Northuldra–the scene with Yealana and Honeymaren. (Anna, as the other side of a bridge returns to bestow the boon into Arendellians–the scene with Mattias and the soldiers.)
Elsa turns The Journey inside out and completes the circle. We see that the circle of The Monomyth is divided into three sections. The first, outward line of Elsa's Journey follows the scenario: Separation(she needs to save Arendelle); Initiation(fighting with the Spirits); Return(returning to life)
But then, since Elsa completed not only the Journey in the outside world, but also an inner spiritual Journey, then her inner line goes the another way. Having found the true home intended for her by the birthright, the sections of The Monomyth circle go the another way around: Separation was with the Forest and Achtohallan; Initiation(she discovered the truth about her status as the chosen one); and Returning to where she is meant to be: in the Forest, with Achtohallan, Northuldra and the Spirits.
Step 14: Rescue from Without ✔
"Oftentimes the here needs a powerful guide who brings him/her back to life, especially if the person was wounded or weakened by the experience".
Anna was her rescuer, who helped Elsa to return to her true new home: because she completed the mission. Elsa was resurrected by Achtohallan.
Step 15: The Return Treshold ✔
Returning to The Monoliths, (scene when she hugged Anna) was The Return Threshold for Elsa. When she resurrected, she carried with her "all the wisdom obtained in the quest to share it with the rest of the world". The wisdom of the both worlds: spiritual and human.
Now Elsa has the connection with her old home and its people and the new home with its people and beings; she has learned both, and truly is The Master of Two Worlds: the ruler of nature, the ruler of people.
(After doing the next right thing in the Forest and using the spirits for her own purposes, Anna got influence on the Forest: a semi-master of that world. After that, she receives the status of the queen and marriage, coming back with new powers and acquisitions. She is now the Master of Arendelle.)
The last steps, Master of Two Worlds ✔ and Freedom to Live ✔
We can see Freedom to Live in the final scene, where Elsa rides Nokk with pleasure breathing fresh air("not anticipating the future")
(Anna and Kristoff now live a happy live "in the moment...not regretting the past".