In this addon will add a Playable Link for Hyrules Faction in custom battle, it will also enable players to play as Majoras Faction for Hyrule: Total War 4.0 - 4.3 edition. Please note I do not claim any of this content, all of this content is avaliable in Hyrule: Total War (Just locked away). This addon is most likely buggy. You may suffer from crashes if played with massive armies. Unfortunately I do not have the knowledge of fixing crashes besides reverting back to the vanilla mod. I apologize if it does cause crashes and to have some insurance I have provided the original files with quick and easy, swap over. Enjoy :) edited - I've just noticed Zelda isn't mounted and is on foot. Not sure if that was on my end or an error from the developer. But aiming to patch it as well in this addon. Also playing with the Giant Majora Monster will crash your game, tho the other units will be fine.
Just copy over everything into your Hyrule directory. I've also added the vanilla files of what I have edited to make Linka and Majoras faction playable.