Dain only has a small part in the book, but from what we see, he seems honorable. He made peace with the elves, shows respect to his departed cousin, became king, and went through with the previous deal to share treasure with Bard and the elves.
Dain
He is good.
Treasure from Lonely Mountain (gold and silver for Bilbo).
Bilbo, Balin, Bard, Beorn, Bofur, Dain, Fili, Gloin, Kili and many more.
Dain Rauscher Wessels was created in 1929.
Dain
He is good.
To keep the promises of the dead.
They are relatives, and also leaders of their respective groups of their people.
Treasure from Lonely Mountain (gold and silver for Bilbo).
Bilbo, Balin, Bard, Beorn, Bofur, Dain, Fili, Gloin, Kili and many more.
Their first request was to let them go through to the mountain, but that was not allowed. At the end, Dain took control of the treasure and re-established the dwarven kingdom Under the Mountain.
The great eagles were allies. Beorn was an ally too. And later Dain Ironfoot proved to be an ally.
Dain is Thorin's cousin, a Dwarf from the Iron Hills. Thorin sends a raven to summon Dain and his army to help defend the treasure under the Lonely Mountain from the men and elves after Smaug is slain. Dain and Thorin join forces with the men and elves to defeat the evil creatures. He is crowned King under the Mountain after Thorin dies in the Battle of Five Armies.
The dwarfs resettled the lonely mountain (Erebor) and made it their capital, they forged a strong alliance with the men of Dale (who had helped kill Smaug).
If you are referring to The Hobbit, then Thorin.But, if you are referring to The Lord of the Rings, then that would Aragon.
Jack Dain died in 2003.