This page in our guide for Assassin's Creed Odyssey focuses on the most important choices that can be done in the ninth chapter.
Where it All Began
You meet Alexios/Kassandra on the top of the mountain. Their attitude towards you depends on your previous choices. By making "good" choices you are able to convince Deimos to leave the past behind. Choose the option where you don't want to fight - the family will reunite.
Making a few bad choices and being hostile towards Deimos (i.e. you didn't help them when they were trapped under the tree) leads to a fight. Kill the enemy and then go back to your family home.