There's only one big mystery that has been revealed that could tie into the new story. The Echo, we now know how it works. Considering it can technically be used on demand now that we know the ins and outs of it, this brings into question...what if somebody has been using it for their own personal gain? Perhaps our next threat is not an Eldritch Abomination, but another who can use the powers the same as us, except they're not afraid to body swap to reach their goals. Every time we think we've stopped their plans, they've body swapped to a new host to continue them. An enemy who we cannot defeat easily because they display the exact same powers as us. An enemy who we may even agree with on their goals but not how to reach them.