In Book Three , he is also revealed to have a strong friendship with Roku , leading to the observation that some friendships are strong enough to transcend lifetimes .
In Book Two , he is seen in Aang 's dream sequence .
In Book Three , Aang is also revealed to have a strong friendship with Roku , leading to the observation that some friendships are strong enough to transcend lifetimes .
In Book Two , he is seen in Aang 's dream sequence .