We're still waiting to find out who that top secret cameo in WandaVision belongs to, after the penultimate episode passed by without introducing any new major characters. In fact, it almost felt like something of a filler outing, with Agatha Harkness forcing Wanda to relive her own traumatic memories that offered some extra insight into the backstory of how we got to this point, but it didn't really drive the plot forward in any sort of meaningful fashion, at least until the post-credits stinger.