Abhai can be found in the campaign Northern Rebirth, in the 5th scenario The Pursuit, in the flooded path (x;y=29;29).
Abhai grew old and died as all men do and entered the land of the dead. He doesn't know how long he dwelt there, he was wrenched from his peace and forced into this ectoplasmic body by Malifor's terrible power. Malifor tried to break Abhai's spirit into mindless slavery, but he resisted his power and fled. Abhai have been hiding in these flooded tunnels ever since. Some monster that Malifor's minions greatly fear lives in these waters; they do not molest Abhai here.
Abhai is so old that time zone is different for him. He first thinks Tallin must have been sent by the High Kalian of Hiera'Shirsha. He is the one who know the most about the Rod Of Justice, though he cannot wield it.