@King
Thank you for your responses. They're very well thought out.
In spite of Bakugou's fantastic intelligence feats of his own, in particular in combat, it's simply incomparable to a guy whom, in a single hour, could learn a language completely foreign to his planet and partially reprogram a living demon to prolong an entire arc in a series. As well as someone that can calculate laser trajectories on a whim with a multitude of different shaped mirrors around, and maneuver both himself and gash to the right position to be untouched by them. He also consistently fires into the heart of strong attacks with Zakeruga to tank through them. He did this against Bari when the latter had destroyed the floor underneath the duo and proceeded to launch a giant gigano class spell. I believe you mentioned destroying the ground beneath them before following up with an explosion. This commonly employed tactic would make this difficult. Not to mention that blowing up the ground could potentially expose things such as metal pipes underneath, from which point jikerudo becomes an incredibly potent issue.
One of Bakugou's largest issues is that he's dealing with two people. One who is much more intelligent that he, despite Bakugou having greater battle experience. And one who can tank pretty much everything Bakugou throws at him, even his higher AP attacks (Gash's durability is much higher than his AP in this key). The same cannot be said for Bakugou.
Stun grenade, much like Gash and Kiyo's jikerudo, is Bakugou's largest asset here. However, there is still the issue of his body odor. Light doesn't make them physically unable to move, and I very much doubt that they would merely stand there when they know there's a risk to their book. Furthermore, if it coincides with Kiyo casting a spell, Gash would be momentarily unconscious, and therefore not blinded by the spell. But either way, Gash should be able to track Bakugou with his nose. He's immensely protective of his book keeper.
Generally speaking, it'll be pretty hard for Bakugou to get close to Kiyo because of Gash. And if he really focuses in on Kiyo, he runs the risk of taking serious damage from one of Gash's spells. Kiyo isn't much of a fighter himself, but he can abuse the fact that it's two versus one to do things like throw rocks to distract him or alter his flight path into a wider ranger Zakeru.
Lastly, there's the issue of Bao Zakeruga, which would arguably one shot Bakugou. It's absolutely massive and incredibly unlikely to be dodged. Even with speed amplification, the size still makes avoiding it difficult due to the sheer distance he would have to travel. Even then, it travels so he'd have to try seriously hard to avoid it. And in that time, Kiyo could easily have a trap waiting. He might even blow up the ground on purpose hoping to find metal pipes underneath so he can stop such a mobile target. And, of course, there's always the possibility that Kiyo fires it from point blank range, which leaves Bakugou with little change of dodging it. I could even see Kiyo baiting Bakugou with the Rauzaraku timer, such that when he thinks he has an opportunity to close the distance with his speed, there's a giant dragon of lightning staring him down.
That aside, Bakugou's fighting style will likely appear fairly straight forward to Kiyo. This "limitation" posed by books is primarily limited to how many spells one has. And their use to a certain extent. Gash's first spell is lightning, and can be used as such. Zakeruga can be used in a similar fashion. (Later on Zakeru is bright enough to blind foes upon a casual casting). Explosions, fire, light, and flight bring nothing new to the table. Similarly, lightning is something that Bakugou has seen before. I believe both their move sets are rather limited (even with how versatile the characters make them out to be), so the battle primarily comes down to small advantages, and general intelligence.
Gash and Kiyo have better range generally speaking, and a numbers advantage which offers them a range of tricks that Bakugou doesn't have access to, acting solo. Such a fact even offers to offset his speed amplification, as he can only target one of them at once depending upon how far they are. And if they split up by 180 degrees, he can only physically see one of them. Kiyo's superior intelligence makes him more likely to come up with plans that Bakugou wouldn't think of. Such as Kiyo's much higher propensity to use and abuse the battlefield he's on much more than Bakugou, and his ability to often times understand the powers and ability applications of others better than the user themselves (I.E. Kyanchome, Tia, etc). Gash's higher durability and stamina means that he'll be able to take more hits than Bakugou, and fight for a longer period of time. And Bao Zakeruga as a potential one shot gives them an explosive option that Bakugou has no real reason to see something. Beams, shields, and arcs of lightning don't suggest shooting a massive dragon of lightning from one's mouth that moves fast enough to hit characters that can dodge point blank Zakerugas (which is confirmed faster than Zakeru). Bakugou's advantages seem to primarily lie in his better mobility, stun grenade, and ability to adapt. Yet his ability to adapt seems to be not quite as good as Kiyo's (though still rather excellent). His mobility is somewhat offset by 2 v 1 tactics, better range, Rauzaraku, and Zakeru's landing AoE. And his stun grenade was addressed earlier.
While I believe the fight to be rather close, Kiyo and Gash's advantages seem to be a bit more numerous and arguably more effective than Bakugou's here.
