Invested people in the Cognitive Realm
Just started reading Rhythm of War and Mraize tells Shallan that people who are heavily invested can't go far outside their world when they are in Shadesmar because they are too strongly Connected to the world. We also see this in Secret History where Kelsier can't go too far outside where Scadrial is in the Cognitive Realm. How then, has Vasher/Zahel managed to arrive at Roshar? Is it because he's storing his Breath in objects while travelling? But then wouldn't the objects themselves perhaps not be able to go with him? And also his single Returned Breath can't really be put into an object I don't think, though he has managed to suppress it somehow. And Hoid of course has a ton of Investiture from a variety of worlds, which can't all be stored like Breath, so how is he worldhopping?