The Legend of Zelda vs Kingdom Hearts
Connection:
Both of them grew in humble lands where people thrived (Kokiri Forest and Destiny Islands respectively). They were sleeping in their rooms until destiny came in to disrupt while simultaneously granting their wish for the outside realms
Both came across many darkness on their path, some minuscule some massive, but then they met a girl, a princess's kingdom threatened by the main cause of the darkness, and they gained a weapon they were chosen to wield, which enabled them to use their main skills and powers (The Master Sword and the Keyblade respectively).
As years passed, both learned that they aged considerably from the boys they use to be to stop darkness once again and did this task alongside friends (Navi for Link and Donald and Goofy for Sora).
After defeating the big bads they returned to their old homes, but not before they said their goodbyes and thank you'd to the princesses who they were close too, after which they voyaged on a journey meeting new people in peril and vowed to help them with new powers they gained.
Though their journeys have a similar purpose, one could not handle being alone and making others happy, falling into depression, while the other's happiness was gained from his friends and was so happy to be with them that he continued to smile with his friends being his power.
After a long perilous journey, both face the ultimate consequence making them a wandering spirit whose body is either old and battered or frozen solid and their spirit wanders one with so many regrets, the other so much to give others.
