Evidence for Drake & Kaido

[Uchiha]

I've seen this a few times but never seen evidence for it? Where's the evidence that Drake is working for Kaido?

 

[SSJ2]

They showed him taking over one of Kaido's small islands. Someone stated that he went under Kaido's wing, will search for it.

 

[SSJ2]

From the wiki:

He now appears to be subservient under Kaido, as he was standing with Kaido's subordinates.