If you do Arah Storymode BEFORE you do the last quest in your Personal Story called ‘Victory or Death’, you are FORCED to repeat the Arah Storymode in order to fully complete the personal story.
This essentially forces you to kill Zhaitan twice, and has got to be a bug. I can’t finish my Personal Story now unless I kill Zhaitan, despite the fact that I already did this one month earlier in the Arah Storymode.
This issue needs to be addressed, the quest is tedious and takes HOURS to complete. It’s ridiculous that players who saved completing their personal story for later are forced to rerun this dungeon in story mode in order to complete the personal story.