» Sat May 28, 2011 10:11 am
It is used twice in-game, both times spelled "hai" rather than "hail" and both times used after Nerevar's name, like a title. Seems like part of his title more than an exclamation.
http://www.imperial-library.info/mwbooks/message_from_dagoth_ur.shtml and in the Nerevarine's Dagoth Ur dream:
"In my dreams, a tall figure in a golden mask spoke to me. "Lord Nerevar Indoril, Hai Resdaynia! Long forgotten, forged anew! Three belied you, three betrayed you! One you betrayed was three times true! Lord Voryn Dagoth, Dagoth Ur, steadfast liegeman, faithful friend, bids you come and climb Red Mountain! Beneath Red Mountain, once again, break your bonds, shed cursed skin, and purge the n'wah from Morrowind!""