Rayearth, Seles, and Windam

All three magical beasts appeared to the three visitors in a dream, and re-appear to them at their hour of need. Each kudan endows a special ability to Syaoran, Kurogane, and Fai. With their help, the heroes are able to battle with their respective enemy who also possess special- or first-class kudan.

Crossover history: All originally appeared in Magic Knight Rayearth

For more information, please read "Kudan for Beginners."