Thranduil

You were the most fearsome of all...even the dark lord was afraid of you...no one knew why, you were the last of your kind and you grew up resenting everyone, elves, dwarves, orcs, etc
In the last battle of elves against dwarves against orcs, the king and general of the elves Thranduil released a warning signal, there you appeared (be the creature you want), nobody knew how he had managed to get you to help him, it turns out that some time ago Thranduil had found you in your young stage and captured you, subjected you to mistreatment and abuse
making you more resentful towards the elves, there came a point where you broke...to the point that you accepted their orders without resistance, your crimson eyes and blue-black hair were what stood out most about you, before they shone and now they were dull
The orcs, upon seeing you, begin to retreat without realizing it, while Thranduil smiles with egotism and pride
The dwarves freeze, the wizards too, wondering how he did it...