Maybe some of the lords of the North who recognize Jon Snow's leadership and his cause. They could bring their own soldiers and resources to support him in the war. For example, the Mormonts have always been loyal to the Starks, and they could be among his strong allies in this fanfiction.
The wildlings might be his allies. After all, Jon Snow has had interactions with them before. They are fierce fighters and could fight alongside him against a common enemy.
Jon Snow could potentially have allies like the Mormonts. They have always been loyal to the Starks. Maybe even some of the Dornish houses might side with him. They have their own reasons to oppose the current power structure in Westeros. And of course, his friends from the Night's Watch who left with him or believe in his cause could be his allies in this conquest. He might also gain the support of some of the maesters who see the value in his leadership for the future of Westeros.
He could meet ancient Valyrian dragonlords. These dragonlords might still have some connection to their dragons, even if the dragons are long gone or in hiding. Another possibility is meeting the descendants of the original Valyrian slaves who have their own unique stories and skills.
Well, it could be about Jon Snow leading his men into a great battle against the White Walkers. Maybe he discovers new strategies or forms unexpected alliances during the war.
It could be a young and untainted Frey. Maybe a niece or a cousin of the more infamous Freys. One who has not been involved in the past atrocities committed by her family and has a more noble heart.
His half - sister Sansa would likely be one of his allies. She has proven herself to be a shrewd politician and would be a great asset in ruling the Seven Kingdoms. Also, the North would most probably stand by him, considering he is a Stark.
Daenerys could be an ally. Since she is the mother of dragons, she might initially be hesitant but then see the potential in Jon Snow riding one of her dragons. They could team up to fight their common enemies.
His main allies could include Davos Seaworth. Davos is a shrewd man and has a lot of experience in the political games of Westeros. He could offer Jon advice on how to navigate the court. Another possible ally could be Brienne of Tarth. She is a skilled warrior and shares Jon's sense of honor. They could fight side by side to protect the king. Also, Gendry could be an ally. He has his own strength and could be useful in battles to defend the king.
In this fanfiction, perhaps Jon Snow goes to Valyria to discover ancient secrets about his heritage. Maybe he finds lost Valyrian steel - making techniques or uncovers hidden knowledge about the White Walkers' origin. It could also be that he meets some long - lost relatives or discovers a new power source there.
In this fanfiction, one of the key battles Jon Snow might participate in could be the Battle of the Whispering Wood. His skills as a fighter would be put to good use there, sneaking around and taking out enemies. Another could be a fictional battle near the Wall, where he defends against some new threat that has emerged during Robb's war.
Allies could include the remaining Stark family members. They would surely support the baby as it is part Stark through Jon. The Unsullied might also be allies as they were loyal to Daenerys. As for enemies, Cersei's remaining supporters could be a threat, seeing the baby as a rival to any power they might still hold. Also, the Night King's followers (if any still exist) could see the baby as a new target, a symbol of the new life they oppose.