How did Mikasa return to Paradis?
Much is debated about Mikasa's "impossible journey" from Fort Salta to the tree in Shiganshina. The common criticism is that she had no supplies, the distance was enormous (the equivalent of Africa to Madagascar), and the Ackerman powers had disappeared. However, analyzing the clues Isayama left in the manga and anime, the return is entirely coherent. Here is my theory:
- The use of technology and communications
We must not forget that the world of Attack on Titan already possessed advanced technology. During the final battle, we saw Secretary Muller use radios and transmitters to coordinate the airship attack. Mikasa, after years of living with the Anti-Marleyan Volunteers, knew this technology existed.
It is very likely that Mikasa headed to a nearby coast. Before the destruction of Odiha, we saw that lighthouses and electricity were functional; the world did not instantly return to the Stone Age.
- The Azumabito factor and the logistical "bridge"
We know that Kiyomi Azumabito ended up in Paradis alongside Queen Historia, and that Yelena ended up on the continent with Onyankopon (confirmed in the anime). This proves that there were ships moving between the continent and the island shortly after the Rumbling.
My hypothesis: Mikasa headed to a less affected coastal area. Given that Kiyomi's lifeboats were near the coast after her ship sank, the meeting distance was much more favorable. If Kiyomi had previously given Mikasa contact information or radio frequencies (due to the Azumabitos' interest in her), Mikasa could have coordinated an extraction.
- Transporting Eren's remains
One of the biggest criticisms is the decomposition of the remains. However, Mikasa is an experienced soldier. Based on what we saw in the Trost recovery arc, she could have cremated Eren's remains to transport his ashes. This facilitates the journey, avoids hygiene and health issues, and follows the Survey Corps tradition of honoring their fallen.
- Infiltration into Paradis
Paradis was in chaos: the walls fell, the high command (Pixis, Nile, Zachary) died, and a large portion of the radical Jaegerists also disappeared. With Historia Reiss as Mikasa's personal ally, the Queen could have facilitated a discreet entry through a private coast, providing her with horses and supplies to reach Shiganshina without being detected by civilians or extremists.
Conclusion
Mikasa's journey was not a 7,000 km trek. It was a survival operation where she utilized:
*Radio/Technology to call for rescue.
*Political connections (Kiyomi and Historia) for maritime transport.
*Military experience to manage resources and the transfer of remains (ashes).
Three years passed before we saw the Alliance again. That time is more than enough for a soldier of Mikasa's caliber to manage crossing the ocean with the humanitarian aid that was already being deployed on the continent.