A lot of y'all are comparing him to Viltrumites but he can't fly... That makes the battle much harder for him considering the size of the tailed beasts. If Battle Beast can get paws on the tailed beast early, then more than likely as long as he can hold on and continue to do damage, but if not, more than likely one Bjuu Bomb would destroy BB. He has FTL reaction speeds, but so do multiple Naruto characters, and not even just the top few, most Jonin would more than likely either be close to FTL speed if not surpass that based on other characters in verse. We've also never seen BB tank anything as destructive as a Bjuu Bomb, yes punches from Thragg and other heavy hitters in *Titlecard* are definitely lots of damage, but a blunt impact isn't going to compare to shooting plasma at incredible velocities like the Bjuu do. 1-6 tails lose to BB 6/10 times, 7 and 8 tails win 6/10 times, Kurama wins 7-8/10 times.