1. The Hyuga Clan (also known as the "Byakugan Clan") possesses the ability to manipulate their bones, which is their bloodline limit. They don't need weapons as their tough bones provide excellent defense against any physical attacks. When they attack, their bones transform into powerful spears. Their high-density bones are incredibly strong, resembling steel. However, if this clan also knew the Eight Gates... 

2. The Uzumaki Clan has a long history and, despite their low-profile nature, they couldn't escape the fate of extinction. This is mainly due to their sealing techniques being too powerful, capable of sealing tailed beasts and becoming jinchuriki, which instilled fear in others.

They were attacked en masse, leading the surviving clan members to go into hiding and scatter around the world.

3. Blood Pond Clan has the Blood Dragon Eye, an illusionary jutsu that is not inferior to the Uchiha Clan's Sharingan. Once caught in their genjutsu, there is no escape. They can turn enemies into human bombs. Although a formidable clan, only Aino and her father, Oyashiro, remain today.

4. Kamizuru Clan is a clan capable of controlling the battles with their secret techniques during the Ninja World War. Their member's numbers dwindled significantly during the war. A single clan member could determine the outcome of a war, possessing powerful forbidden jutsu.

Now, in Naruto's generation, only Hotaru hides the forbidden jutsu within herself.