Foe Yay: Bomberman and Regulus/Bulzeeb. Bulzeeb is very eager to settle the score with Bomberman, and even does The Only One Allowed to Defeat You schtick by saving him from Zoniha. Even the other Knights note how Bulzeeb gets excited whenever Bomberman is brought up. Then there's a comment about how he "makes his warrior's heart sing" in a cutscene if you clear Aquanet after Horizon. Bomberman also seems enthusiastic about having their eventual rematch in the good ending.
Fridge Logic: Obviously this was done for the purposes of working with the gameplay and resulting story, but — it's kind of weird that Bomberman as a bomber wasn't able to utilize his ability at all without the Fire Stone on his person. Where does that leave the other bombers in this universe?