If you had read the description fully, you would know that the first two fusions have been swapped.Ah that is why!
Debo is now found in Guntz, and costs 10 AP. It fuses Danq with Gobi and Bild, but can only be used underwater. It is now available for use during a portion of the story in which you'll actually be underwater. Before, you obtained it after you were done in the sea and it had no purpose.
Cheyenne is now found in Gust, and costs 15 AP. It fuses Danq with Gary and Gobi, and like Gary, can walk through forests (As of v1.03). Before, no one had any reason to use Debo over Cheyenne aside from exploiting the Game Over bug.