In episode 21 of season 3, Eren Kruger
who is The Owl (Former Attack Titan), told Grisha to save Mikasa and Armin despite the fact that they were not even born at that time.
How could he
access the memories of a future Attack Titan?
Is this an ability available to
all Titan shifters?
If so, then why was Eren Kruger the first to manifest it?