D.Gray-man, Hunter x Hunter (2011) Recommendations
Both shows are action shonen with well thought out stories and good action scenes. Also, in both shows the MC work hard towards a goal. The MC's are quite strong and there are no random bursts of power making the MC over powered in face of danger in both shows.
-Both are darker, more mature shounen
-Both have lots of death involved
-Both have childish protagonists
-Both have characters that feel more real than other series
I think that Gon was similar with Allen because those two had same personality and also never give up to fight together with their friends.Killua and Lavi are also supporting their main characters and also their friendship.Leorio would be just like Krory while Kurapika would had a same personality with Kanda. The Phantom Troupe would be just like the Noah family and Hisoka would be had a same personality with Tyki Mikk.