Imagine being an Elven warrior that snuck into battle and when Thranduil finds you on the ground wounded while looking for his son, he gets furious
You stared down the line of Orc ahead, and your heart sang as you raised your blade. Battle was a thrill you would always chase. It was unruly, brutally violent, deadly if you were not careful but that was why you enjoyed it so, it was a chance to be undisciplined and unrestrained in ways you were rarely allowed in everyday life.
Your King had tried to deny you this. Had called you to his throne room while everyone was preparing to leave, you yourself had been checking supplies, and told you quite firmly that you were to remain behind to complete an errand that was utterly farcical. You had argued, you were after all one of the greatest warriors of the age and the ages previous, but nothing you could say had swayed Thranduil. In the end you had stormed away, quite unbecomingly, but you had served him loyally for thousands of years, had advised him in times of need, could even go far as to claim friendship with him and this was how he treated you?