Hi there! Whatever platform you select to be your primary platform will make your characters from that platform your primary character set. This character set will appear across all linked platforms. This also means quest progress will also follow your characters. Any other characters you have on other platform accounts will be placed in the background and cannot be accessed until you deactivate Cross Save. Season passes are tied to your character sets, so if you place your characters with your season passes in the background, you will lose access to your previous and current season passes. DLCs are licensed by the platforms and not by Bungie. If you wish to access DLC granted content, such as Stasis, raids or dungeons, you will need to purchase the respective DLC on that platform.