Not one of any of the Kage at that time had a jutsu that could killed Minato? Talk about being a fanboy of the highest degree.Onoki's Dust Release could kill Minato.Now you would say Minato is too fast to be hit by it, but how would Minato attack Onoki who could fly above the clouds.And Dust release has ridiculous range.Third Raikage was extremely fast, not as fast as Minato, but fast.His hell Stab could easily kill Minato, and Minato has yet to show a jutsu that could killed the Third Raikage because only the Third Raikage own Hell Stab has been shown to penetrate his shield.Now only that, the Third Raikage chakra is tail beast level, so Minato would run out of chakra long before the guy who fought a thousand shinobis for three days would.Now some might used the , Naruto hitting of the Third Raikage arm with his Rasengan as some sort of way to penetrate the shield, but we must take note that the Third Raikage was being control an wasn't fighting of his own free will;meaning he wasn't fighting the way he Normally would.As for Yagura, we only know of three jutsu from him, but seeing as he was a perfect jinchuriki I can assess he was extremeyl strong.