The real life Deep Impact was an obvious short-lister for the franchise, having made a tentative appearance in a 2016 promotional video. However, due to the alleged controversy arising from the franchise's bastardization of King Kamehameha (which share the same owner, Makoto Kaneko), he and Kaneko's other horses are unlikely to officially appear beyond allusions made in-game, Black Tide is his full older brother. It can also be noted that Aoki Ruriko, currently the voice actor for Air Groove, was at one point going to voice this character, which indicates how early on the decision to shelve the character was made.
So far, seven of his progeny appears in the franchise:
