These are the Johto Region Legendaries.
Much like the birds, it possesses the ability to control the weather; most notably, it can calm and give rise to storms. You can find him inside the Lugia Tower and you need to have the three legendary birds.
*It's a wave form so it does the same amount of damage repeatedly as long as the player is being hit by the wave.
Ho-Oh has a mythical power to resurrect the dead. Ho-Oh is the only known Pokémon to learn Sacred Fire. It is said that when it flies its huge wings create bright, colorful rainbows. You need to have all of the legendary birds.
They all share similar attributes and are considered equal among themselves.The legendary beasts also share a master in Ho-Oh. All of them can be found in the Brass Tower that spawns in the middle of the field. You'll know it is appearing because everything gets really laggy.
Raikou is said to represent the lightning strike which ignited the fire that consumed the Brass Tower.
Entei is said to represent the flames that burned the Brass Tower.
Suicune is said to represent the rains that quenched the flames of the burning Brass Tower.