Question about back from SSF to normal league

If I return my SSF character to a normal league will it take its items? What if I already have a character in a normal league, will those items be merged?

I think theres just a character migration or full migration, later merges everything including stashes, atlas progression, etc where the former is just your char + their gear/inv.

Its nice when you play both leagues and find stuff in ssf thats worth a lot but cant use, you can just make a lvl 1 char throw loot on him and migrate to trade and sell that stuff, while keeping your ssf characters there.