Board Thread:Manga/@comment-27441457-20170608195407/@comment-28958062-20170609083812

The only reason I can think for Eren to in Liberio is to turn every single Eldian there into a titan like Zeke did to Connie's village and start a massacre on Marley plus getting rid of every titan shifter of theirs while giving a window for the Walled people to start a full scale attack.

It's plausible that Eren learned how to use the coordinate in those four years so he can control every single titan to do his bidding and avoid friendly fire.