Okay the how about a test then let's see if you can understand this guy. [He takes out a pokeball and give it a small toss. What pops out is a Milotic]

Hey Kurapika, no battles this time, just need you for a chat.

[Kurapika just give Killua a curious look before nodding and making an oddly musical sound. ]

Alright then Killua. [Killua just accepts the nod but understanding the qist of what his Milotic is saying.]