dhruvo bhratr-vadham srutva
jaitram syandanam asthaya
dhruvah—Dhruva Maharaja; bhratr-vadham—the killing of his brother; srutva—hearing this news; kopa—anger; amarsa—vengeance; suca—lamentation; arpitah—being filled with; jaitram—victorious; syandanam—chariot; asthaya—getting on; gatah—went; punya-jana-alayam—to the city of the Yaksas.
When Dhruva Maharaja heard of the killing of his brother Uttama by the Yaksas in the Himalaya Mountains, being overwhelmed with lamentation and anger, he got on his chariot and went out for victory over the city of the Yaksas, Alakapuri.
Dhruva Maharaja’s becoming angry, overwhelmed with grief, and envious of the enemies was not incompatible with his position as a great devotee. It is a misunderstanding that a devotee should not be angry, envious or overwhelmed by lamentation. Dhruva Maharaja was the king, and when his brother was unceremoniously killed, it was his duty to take revenge against the Yaksas from the Himalayas.
Link to this page: https://prabhupadabooks.com/sb/4/10/4