The Guardians Of The Lake.

In the Sinnoh Region  Azelf, Mesprit and Uxie are known as the lake Guardians.

They are immensely powerful beings that rule over an aspect of human and Pokemon life.

Azelf is known as "The Being of Will Power"

Mesprit is known as "The Being of Emotion"

Uxie is known as "The Being of Knowledge"