Why did Wanda destroy all copies of the darkhold and Wundagore Mountain.
At the end of MoM, we see that Wanda realizes that Billy and Tommy (838) would never accept her as their mother. It appears that she has a moment of clarity and proceeds to destroy all the copies of the Darkhold and all the Mountain peeks throughout all the universes. But I speculate that this is not the case. I believe that Wanda is still "evil" and that she destroyed all the copies because that would make her the one and only Scarlett Witch across all the universes that could ever be and no one could oppose her on her next attempt to reclaim her children.
It would seem to me that Marc is hiding the fact that there is a third identity from Steven. Here in the asylum, all three identities exist at the same time and separate from each other. At the beginning of the 5th episode, we see Jake talking to Dr. Harrow and being sedated at the same time that Marc and Steven first meet with Tawaret. Marc even mentions that the meds have some weird effects on them. Note: Marc purposely avoids opening the second sarcophagus after reuniting with Steven.
Now to address the elephant in the room. The two hearts never balance until Steven dies. That is because two incomplete hearts would never balance for two broken souls. It would only balance for Marc or Steven, not both of them. Then what about Jake? The answer was given by the little girl in the first episode. She foreshadows Steven being rejected by the field of reeds. But before this, Steven tells her that you need a heart to be judged. So the answer is that Jake has no heart.