A great man with great skills

Drona was a great man with great battle field strategy and skills. He was the teacher of both Kauravas and Pandavas who taught them all about battle fields and weapons. His so called Chakrabyuha was a battle formation where a enemy can easily enter but cannot get out from it. A trap that is really dangerous and cannot be broken except his best disciple Arjun. He was one of the best teacher and skilled person in field of battles and weapons.

For a great man like him with great skills and sense of justice it was really hard for him to fight again the Pandava's specially Arjuna one of his best and dear disciple. But still his loyalty couldn't betray so though unwillingly and with a heavy heart he went against Pandava's.