A mission failed and Ezra was abandoned by everyone except Kanan, Hera, Ahsoka and Rex. After he was abandoned Vader found him and took him as his Apprentice known as Starkiller. After some years Ezra had to run away. After Leia found him and Ezra sensed she had the Force so he took Leia as his Padawan. Story in cooperate with AshuraSkywalkers