Gita Post #6 Drona and Kṛpa on the Kaurava side are seasoned warriors of extraordinary skills, and Karna is ever confident to challenge Arjuna in archery. All the same, Duryodhana is hopeful of winning the war and the Kingdom only as long as Bhīshma is alive, so he wants everybody to protect the old Kuru alone.
Gita Post #5 A brāhmaṇa is a teacher of dharma. His functional role by nature (svadharma) prohibits him from himsā (hurting or killing). Drona’s presence on the battlefield as an army commander is to show that dharma is now at its worst.
The genius of the author of the Mahābhārata conceived in Kṛshṇa a model, which epitomizes Brahman (the Absolute) and appears on earth in the human form. Vyāsa's Kṛshṇa is Brahman, the universe, the guru, and an ideal human being at the same time.
