Brothers in Arms (The Witcher 3: Wild Hunt)

AmalPower
(Taken from the post http://www.playground.ru/blogs/witcher_3_wild_hunt/vedmak_3_dikaya_ohota_kontsovki_v_igre_vse-144637/)
Spoiler I would also like to note a couple of points related to the battle in Kaer Morhen.
Before this battle, you will have the quest "Isle of Mists", where you will need to find Ciri.
Along with this quest, you will receive the quests: Brothers in Arms: Novigrad, Brothers in Arms: Skellige, and Brothers in Arms: Nilfgaard.

If you want to complete the "In Full Force" achievement, then you will need to ask for the help of 7 allies (2 of which are very easy to miss).

1 - Keira Metz
(Velen, ask her to go to Kaer Morhen at the end of her side quest instead of killing her or sending her to Radovid)

2 - Triss Merigold
(Novigrad, complete her side quest "Now or Never". At the end of this quest, you must ask her to stay and confess your love to her. After that, she will go straight to Kaer Morhen)

3,4 - Roche and Bianca
(Novigrad , complete his secondary quest "An Eye for an Eye", then talk to him during the quest "Band of Brothers: Novigrad" and he will go to Kaer Morhen, taking Bianca with him

5 - Zoltan Chivay
(Novigrad, just talk to him during quest "Band of Brothers: Novigrad)

6 - Myshovur
(Skellige, just talk to him during the quest "Band of Brothers: Skellige)

7 - Hjalmar
(Skellige, complete all the quests related to the ruler of Skellige. Regardless of your choice between Hjalmar or Cerys, Hjalmar will go to help you in Kaer Morhen.

There are also characters in the game that you can ask for help during the Brothers in Arms questline ". Some of them will also be able to come to your aid if you helped them with side quests. The achievement is not affected in any way.

1 - Emperor Em Gyr
(Vizima Palace, in case of a conversation with him, he will report that he will send a banner along with the general , but Geralt refuses this venture. Perhaps there is some alternative outcome, but it is not yet known for sure)

2 - Summer
(Velen will gladly come to the rescue if you complete a side quest with him and offer to go to Kaer Morhen)

3 - Sigismund Diikstra
(Novigrad. It is not yet entirely known whether he will come to the rescue, because in my case I did not help him find the treasury. If anyone knows if he can help, then unsubscribe)

4 - Folan
(Skellige, he will come to help with Hjalmar)

5 - Vigi
(Skellige, during the quest "Lord of Undvik" save him from the giant's cage, otherwise he will die. He will come to the rescue along with Hjalmar)

6 - Crash An Krayt
(Skellige, after the conversation will report that cannot leave the islands, but will give you a very good silver sword)

7 - Cerys An Craite
(Skellige, if you chose her as the Lady of Skellige, then be sure to talk to her and she will send Hjalmar to help you)