BB already have Logia and Paramecia. The last is Zoan.
Who was Law's patron? Corazon. Who was Corazon's patron? Who will protect his boy's boy Law?
Sengoku.
Just maybe, Teach attack on Law is somewhat of a bait. The one he actually targets is Sengoku, so that he can achieve Devil Fruit of Daibutsu.
Making him into a Buddha, possessing dark nullifying power, natural disaster power, and also divine power. Imagine Evil God Golden Buddha version of Teach sending quake-infused golden beams.