He's not the strongest.The Ten Tails is.The 9 tails is the strongest of the 9 tailed beasts.Even though the 10 tails is a combination of the 9 tailed beasts he still is the strongest9tails. he's the strongest of them all.
1- Jiraiya stopped it once that is why itachi said to kisame we would be dead if we fought him and for the same reason i say naruto would beat kisame because naruto is way stronger than jiraiya1. It doesn't matter if it has a slower effect (which doesn't) the fire is indistinguishable. Once the fire starts its impossible to stop it.
2. Amaterasu hit first before Sasuke cut the tentacle. Which means that all killer Bee was burning.
Sasuke did not kick Hachibi's ass xD Just because he got in an Amaterasu doesn't mean that he did and even then Killer Bee tricked him in the endno no no you got it wrong bro 9 tailed beast = 1+2+3+4+5+6+7+8 tailed beast power combined as you can clearly see the 9tails have only half of his former chakra but still strong enough to give pain hard time we have seen killer bee go full 8 tailed power but kisame and sasuke kicked his ass ( i know u said only tailed beast no Jinchūriki but killer bee with 8 tails= Hachibi in full power)
P.s naruto with drop from the kyuubi chakra was able to beat garaa's 1 tailed beast
yes 100/100 rightSasuke did not kick Hachibi's ass xD Just because he got in an Amaterasu doesn't mean that he did and even then Killer Bee tricked him in the end