Answer: No, the game won’t have the ability to do that. But you can create a group chat and invite that player into your group chat.
Some extra relevant information:
No, it is not possible to add a player from a different alliance to another alliance’s main chat in the game Rise of Kingdoms. Each alliance has its own separate main chat, and players can only communicate with others who are part of the same alliance. The main chat serves as a private space for alliance members to strategize, coordinate activities, and socialize within their own group. If you want to chat with players from different alliances, you can use the Kingdom Chat or other forms of communication outside of the game. However, keep in mind that sharing sensitive information with rival alliances is not advisable as it can compromise your alliance’s strategies and plans.