A Tailed Beast Ball is the ultimate technique of a Tailed Beast. Although every Tailed Beast can perform it, few Jinchuuriki have managed to be able to use it.
Here are all 7 users of the Tailed Beast Ball. Naturally, Tailed Beasts won’t be included.
Yagura was one of the few people who had complete control on his Tailed Beast. Naturally, he could also transform into Isobu completely and also use the Tailed Beast Ball. Moreover, Yagura was also able to take on two members of the Akatsuki at once and managed to kill one.
6. Killer B
Killer B, the Jinchuuriki of Gyūki, was also able to undergo a complete Tailed Beast transformation. Also, this makes him a user of the Tailed Beast Ball. Killer B demonstrated its destructive powers against Team Taka among other times, where he incapacitated all of them.