Applejack promised her friendship with her friends will prevail even after they returned the elements.  
she couldnt keep that promes, because at the end her friendship broke.  
this was a tragic event.  
After leaving her friends, Applejack dedicated her life to protect other pronies from problems, and keep families safe.  
she lost her eyes saving some fillies from some griffons.
 
years later, she re-encounters with twilight, but twilight is no longer a princess, but an empress who make the world suffer. applejack try to kill her but fail.  
twilight get some hostages, forcing applejack to sacrifice herself.
 
Kenshiro is on the way to save Applejack. mean while, applejack is forced to carry a giant piece of twilight empress monument
 
Applejack couldnt get over how her friendship was broken.  
“A foal until the end. She thinks the fall of their frienship is her fault.”
 
Kenshiro get in the place, but is to late, Twilight killed Applejack.  
Kenshiro run to applejack. she asked to the heavens to look at kenshiro, to know the face of the new savior of Equestria  
The heavens grant this wish to her, giving kenshiro her blessing, and passing on.  
But Applejack is sure of something:  
“Her destiny as the Element of Honestyhas not been a mistake after all”