Though Túrin, a mighty warrior, was cursed by Morgoth (Sauron’s master, from way before the events of The Lord of the Rings), he had the opportunity to escape the curse—but he continually made terrible choices that brought pain on himself and ruin and death to everyone around him. He tried to do the right thing, but his pride continually prevented him from doing what was best.
Túrin had his excellent qualities: he was strong, skillful and brave in battle, and compassionate to the needy, and he had a strong sense of justice. But all of these could not overcome his pride, hotheadedness, desire for glory, and refusal to listen to wise counsel. In fact, his strength and charisma only made the effects of his pride and rashness even worse.
What Túrin teaches us is that a strong and compassionate person will still cause suffering and bring ruin if they allow themselves to be arrogant and foolhardy, ignoring good advice and seeking glory and revenge.
His story is told in a chapter of The Silmarillion, Tolkien’s great history of Middle-Earth from its beginning through millennia of the war of the elves with Morgoth, and in The Children of Húrin, a novel.