Great Lions of the Past

"And the clouds! They turned into roaring lions!"

- Chungu, The Lion Guard: Return of the Roar

The Great Kings of the Past are deceased rulers of the Pride Lands who watch over and guide the living.

Information
The Great Kings of the Past control a great power called the Roar of the Elders, which is bestowed on the second-born cub of the monarch, who is also tasked with leading the Lion Guard. The Great Kings control this power's use and can take it away if the user does not respect their gift, as was the case with Scar. They have the ability to appear partially formed in the clouds and communicate with the living.

They are also responsible for choosing the next Royal Mjuzi for the next generation of the lion royal family.

The Lion Guard: Return of the Roar
When Kion receives the gift of the Roar, he uses it to free his best friend Bunga from the clutches of two villainous hyenas. The Great Kings can be seen roaring alongside him in the clouds. Rafiki later explains to him why his roar sounded different, telling him that the Great Kings of the Past roar with him when he uses the Roar of the Elders.

The Lion Guard
The Great Kings of the Past appear whenever Kion uses his Roar. In addition, they are featured briefly in the song "Here Comes the Lion Guard", which plays during the credits of most episodes.

The Lion Guard: The Rise of Scar
Rafiki explains that the good kings of the past appear in the sky, their voices are in wind and every time Kion uses the Roar of the Elders. The mandrill also explains that the bad kings of the past are summoned with fire instead of clouds, (but he doesn't mention that it happens once an advisor's staff is thrown into the source of the fire, regardless of whether the staff is from a full fledged advisor, or an apprentice).