Bakugo is physically High 8-C+, and he was incapable of breaking through Dark Shadow. I don't see why he'd be annoyed by DS's defense, if he could one shot him with his pinky finger. We don't see the fully fight, but shouldn't it be logical to assume Bakugo tried to physically break through and failed?
Bakugo in this arc is incapable of compressing his explosions, so he cannot unleash High 8-C+ blast without them being large in size.
If you desire to give him a variable rating for his Quirk, that is fine, his rating would be High 8-C+, varies from 9-A to High 8-C+ with Explosion. His current key does not need such a thing though, since he can compress his explosions to be more powerful than anything he's ever done yet their sizes is incredible small.
That is why I removed Tomura taking an explosion from Bakugo from his dura section, since that small blast shouldn't be comparable to his High 8-C+ level blast.
Once again, should DS's Dura scale to Bakugo's physical strength or should I place him at 9-A?
Also in his second key, Dark Shadow did not survive an attack from Chimera. Dark Shadow was completely blown away, he actually vanished when hit. I don't believe he should scale to Chimera whatsoever, so I believe he should be downgraded as well.
Edit: Just realized that Bakugo is not physically High 8-C+ in the Sports Festival, please ignore the High 8-C+ talk up above.
Dark Shadow should just be 9-A than correct?