In life, the Paladin Deathknight was a Dragonborn paladin of Bahamut, who did not join the freeborn rebellion. He fought his own kind and died to them, filled with a mix of regret, betrayal and torment.
As a result of this, he was relatively easy to revive as a Deathknight to participate in the Dragons' reconquest of Freeborn. At some point he came into the service of Lord Azhna, who eventually sent him as an emissary to Lady Vasarus. However, he could not meet with her due to her recent death at the fins of the Deluvians, so he waited in her cave until The Party showed up. At this point, he attempted to kill them as he considered them interlopers in the cave he had been assigned to guard (Deathknights are apparently not all that up on Laric's inheritance laws, since it was technically Little One's cave at that point). Regardless, The Party re-killed him and Black claimed his mace.