Alpha-sapphire: Ho-Oh’s feathers glow in seven colors depending on the angle at which they are struck by light. These feathers are said to bring happiness to the bearers. This Pokémon is said to live at the foot of a rainbow.Y: It will reveal itself before a pure-hearted Trainer by shining its bright, rainbow-colored wings.X: A legend says that its body glows in seven colors. A rainbow is said to form behind it when it flies.
Prof. Lotus' Notes: Ho-oh is Lugia’s counter part and acts guardian of the shies with 3 legendary Pokemon it keeps in check: Raikou, Entei, and Suicune.
700 years before the events of Pokemon Gold and Silver, two towers were erected in Ecruteak City to celebrate the bond between man and Pokemon, a bell tower, and brass tower where Lugia and Ho-oh would perch in celebration respectively.
200 years later, out of nowhere, a violent storm engulfed the sky and a mighty bolt of lightning struck the brass tower. Being made of wood, the heat and embers from the strike lit the tower ablaze. The storm brought with it rain that doused the fires of the tower. However, that was not the only casualty, with it, 3 Pokemon stuck in the brass tower met their end.
Ho-oH, who perched on the Bell tower, upon hearing the demise of these three Pokemon, used its power and revived them whilst now give them divine powers to represent the sad events that occurred that day. From the ashes, arose Raikou to symbolise the lightning bolt that struck the tower, Entei - a symbol of the fires that destroyed the tower, Suicune - the rains that doused the fire.