Destruction of Sernpidal

Anakin blossomed under Lukes training and got a bit arrogant. Seeing the Force as a tool only. This led to a bit of sibling rivalry with his wussy brother Jacen Solo.

But Anakin soon learned humility.. While on a mission to Sernpidal with his father and Chewbacca they came upon a plot by the alien Yuuzhan Vong to destroy the planet by dropping a moon onto it.

They couldnt stop the moon from falling but they could rescue the people on the planet. Chewbacca died saving Han and Anakin. Anakin blamed himself because he had to abandon Chewie to save the refugees.

It was the hardest decision he ever made. And he has not yet forgiven himself for it.