@doomroar
What? Baku kept his unused Air-Bios out of reach from Lalo, but left his used Air-Bios in Lalo's reach. The used ones were completely emptied, that is, he wasn't actually saving air through the match.
@Haremmony
He's the kind who won't drop a grudge no matter what, as seen during the Minotaur Labyrinth.
Which reminds me, back then Baku actively waited to solve his Labyrinth to ensure that Minowa was dealt with. Was that his way of avenging Marco, who he probably believed to be dead? If we liken that to this situation, he's doing this as payback for Kyara.