Grand Kanoi

The leader of the Yilneh is called the Grand Kanoi, or just Kanoi. Structurally, they're very similar to a king or queen, in that the position is lifelong and comes more from a bloodline than from an election. It's not completely hereditary, but they are usually chosen from the strongest telepathic bloodlines, so tend to come from a lot of the same families.
To become a Kanoi requires a number of psychic tests to ensure that they are the strongest, and also that they use these abilities empathetically and not to harm. The idea is that this is going to be the person who best understands those around them, whose mind is most open. They draw a lot from the idea that the highest leader needs to be the greatest servant.
The symbol of this position is a kind of face mask that fits over the four eyes of the Yilneh. This is likely so the position could not be taken by one of the Vrixid or the Tiwethi, who have broadly different facial structures. It's made of the same substance that enhances their telepathy and is an incredibly powerful artifact.
The Kanoi is responsible for overseeing the people, and being chief in interrelations between the other three species on the moon. They are meant to be approachable, and it is only in times of extremely great strife that they would have guards around them. The whole telepathy thing would make an attack easy to spot anyway.
Of those not chosen to be Kanoi, they are meant to swear oaths of loyalty to the one who is chosen. This is more of a formality in modern times but originally it was a way of compensating for the fact that those left out would probably react pretty badly. Not gonna be on their best behavior.