The Bohrok-Kal are transported to Equestria (curtesy of the black hole caused by the power overload of Nuhvok-Kal) right as the changelings invade, with them deciding to help (after asked by the guard using pictures to communicate thanks to a language barrier) the Equestrians for no other reason than to find a way to home.

7523077
Good point. Heh the Changelings would get pummeled thanks to their powers or worse the normal Bohrok use their Krana to infect them and work for the swarm attacking the Hive and Chrysalis retreats in terror as everyone begins to utter the word Bahrok.

7823628
Krana don't work on beings that from outside the Matoran Universe, besides this about the Bohrok-Kal.

7823629
Oh. What about the Visorak?

7823634
Their venom has limitation.

7823675
Oh ok. How about the Makuta’s sons?