"Raikou, Entei, and Suicune were once Jolteon, Flareon, and Vaporeon? When the Brass Tower in Ecruteak City burned, three Pokémon perished in the fire, and were revived by Ho-oh as the beasts. Jolteon, Flareon, and Vaporeon not only share the beasts' typing, they share their color schemes. 

"Further proving this theory, in Generation 5, Raikou, Entei, and Suicune were given Dream World abilities. Raikou got Volt Absorb, Entei got Flash Fire, and Suicune got Water Absorb... ...The same exact abilities as the original Eeveelutions..."