A few things to note concerning your question, as you're asking two-ish different questions but look like you believe you're just asking one. Firstly, concerning the Migration. When the transfer happens from Blizzard to Steam, your Blizzard Destiny 2 information is being transferred entirely and completely, as long as you perform the migration properly. All of your licenses, characters, and Destiny 2 account data will be moved from Blizzard to Steam. So, yes, if you buy the Complete Collection on Blizzard before the migration, you will still have the Complete Collection after the migration to Steam; you will own Forsaken and the Forsaken: Annual Pass on Steam. Your characters will also be there that you originally created and worked through on Blizzard. Concerning your second quest about having your PS4 characters on Steam. When the Cross-Save feature is enabled, you will be able to access your characters consistently on all platforms. That being said, the Cross-Save details are currently in the works but nothing is finalized and available yet to really give specific details. In the meantime, you can sign up to be notified when the feature takes shape: https://www.bungie.net/CrossSave -- Lastly, the 'ish' question you didn't ask, but only since you mentioned two different platforms. If you purchase licenses on one platform, even with Cross-Save, those licenses don't transfer. So if you later decide to go back to PS4 after you've played through content on PC, if you don't own that content on the PS4, you'll not be able to play that content. So if you buy Shadowkeep only on PC, that license doesn't transfer to PS4, it'd have to be purchased separately, so keep that in mind in the future.