Ok Imma probably have to lay the ground work for this match myself first before MHA supporters add their side.
For starters Shion isn't going to be directly damaging Deku and Bakugo, she's mainly here for the purpose of support and analysis. Well she can unironically spray tear gas in their eyes with her camouflaged drones. Mainly though she's going to look at them once and know about all of Deku's quirks, Blackwhip, Float, the superstrength and smokescreen as well as the fact Bakugo has explosion powers. Nanao has the Nanao eye which will also tell the duo about Deku and Bakugo's special moves like Howitzer Impact or Fa Jin.
Nanao isn't Taiyo or Kyoichiro level skilled, he's still got Yozakura training and all of the Someinine powers (Perception amps and such) but I
dont expect a repeat of this thread to happen.
What actually are problems for Deku and Bakugo are a few things. Even though they have gas masks. Nanao can still just
physically inject you with poison or whatever if he touches you. So he could honestly beat either of them if he either syringes them or submerges them in slime then changes the composition of his own slime to poison em. Blight spider neurotoixin is also standard equipment for him he keeps in syringes.
The duo can't just easily pick of Shion, since as a duo what they do in character is Shion using her bio manip on Nanao to pilot him like a megazord as he can grow to bigger sizes while in slime form. Nanao can also
transmute Shion into slime and transmute her back if he wants to shield her or dive into the Teiou island beach sand and rise back up again for a surprise attack or to dodge a big explosion from Bakugo. Also black whip is completely useless since Nanao will just turn into slime to get out of it despite his LS disadvantage, he can do the same for Shion if Deku grabs her instead. And Shion's Analytical prediction will help guide Nanao on how he should go about fighting these guys.
Something else is that at least as was agreed upon in the Kyoichiro vs Deku thread.
Yozakura's resist danger sense. Combined with Shion's camoflage and illusions via her drones and the duo will struggle to point out where they even really are without resorting to massive aoe moves.
Good luck to whichever one of em gets trapped in this from Shion
Nanao has two stacking blitz amps.
One blitz for Blooming and a blitz above that for TSB, but I'll explain later why Nanao probably isn't resorting to those fast vs Deku and Bakugo. Edit here:
If you wanna know how good Yozakura's can work together, this teamwork section gives a pretty good idea.
On Deku and Bakugo's end. Bakugo has a massive range advantage and the heat of his explosions are notable, he also will know getting close to these two is not ideal since Nanao can constantly spray around hazardous gases. Deku with a max charged Fa Jin could also hurt Nanao quite a bit, albeit a KO from that alone isn't really on the table thanks to Nanao's Low Mid regen + he can turn into slime to just have deku Kick through him. Using that blitz on Shion would be better, since either of them can knock her out in one blow. Deku also has better mobility and range than Nanao and Shion (Smokescreen sucks just had to let the stray out there) and he's got analytical prediction of his own.
Back to the Yozakura siblings. Nanao's morality will stop him from using his most potent hax, that being this True Spring Blooming. Or at least he'd be extremely hesitant about doing so.
Cause of that if they take out Shion maybe the duo has a chance at just trying to tire out Nanao over the course of a drawn out fight. His base blooming he mainly uses in situations where he needs to catch up to a stronger enemy via its AD (or needs to grow to overcome a hax) but he's stronger than Deku and Bakugo here, he prob won't see a need to use it unless he feels he's on the backfoot. He only used his Blooming twice across the manga onscreen after all.
Yeah thats what I got to start with