User blog comment:Pigzillion/How come Killua learnt Nen so late?/@comment-4828844-20150809015327/@comment-5780397-20150809095758

What a wonderful picture.

Anyway, Kalluto's specialty does not seem to be combat, but searching: remember he scanned the whole Greed Island and found an Exorcist. Also, Gon and Killua were invited to join the Troupe when they had only started to learn Nen, so potential might be more important than real power.