Si'ess (see note below) is a Dark Seducer encountered in The Chimera of Desolation at Point A, and serves as your greeter to the Chimera of Desolation. According to The Posting of the Hunt, she is given the role of the Master of the Hunt, whose role is to sanctify the Ritual of the Innocent Quarry, also known as the Wild Hunt. As part of the Ritual, the Master of the Hunt is made invulnerable to nearly all weapons and magic for the duration. Outside her duties to the Hunt, she serves Dagon directly as a spy, while the other Dark Seducers in the level function as Xivilai Moath's gamekeepers.
She appears a second time in Dagon's Hunting Lodge at Point C as Mehrunes Dagon's bodyguard and lover, complete with the Sword of the Moon Reiver, a blade made of Dagon's own substance and one of the items needed to banish the Daedra Prince to Oblivion, entrusted into her possession. While she will not attack the Apprentice directly, she will not relinquish the sword except by force.
Seek about the island. In accordance with the Law, the Offices are posted.
Player Response
Result
And that would be the letter of the Law, I'm sure. Very well. Indeed, the Game is afoot, so catch me if you can. Only be very sure you know what to do with me if you DO catch me.
[&Tattle] A little chunk of ice told me to tell you that Faydra Shardai, not Xivilai Moath, was the architect of the plan to invest and plunder Shade Perilous.
If you think that my master or I care about any such squabbles, you are denser than the Frost Daedra. Such favors and punishments are but means to keep our allies in line.
Player Response
Result
I told the chunk of ice I'd report to you, and I live by my word.
I've heard that mortals are a short-lived race, too short-lived to acquire wisdom. Let us put this proposition to the test. Perhaps first a lesson on showing proper respect is in order.
Player Response
Result
Oh. Thank you. How nice of you. I'll be leaving, then.
I believe my lord and lover may have underestimated you, mortal. It is not a mistake I will make. But I must admit to a certain tingling of curiosity in anticipation of your actions, and your fate. And so I propose the following conditions. Do not offend against me, and I will not offend against you. Offend me, and expect no mercy. Do you agree?
Player Response
Result
Indeed, I do agree, my lady, and in turn offer you the same conditions.
At the risk of seeming boorish, I will not consider conditions of any kind from you or your kind. We are enemies. Arm and protect yourself, for only by arms may we resolve the conflicts between us. Goodbye.
Graciously done, sir. And so, with your permission, I shall return to my reflections upon the abyss. I ask you please to forbear disturbing my meditations with further speech. Good day.
Player Response
Result
I will honor your wishes, especially to avoid giving offense. Good day.
END Command 13 &DarkThink
Certainly I would only disturb you if it were absolutely necessary, my lady. Good day.
END Command 13 &DarkThink
If I need to speak with you, my lady, I will, even at the risk of giving offense. Good day.
An offense against my person, pride, or honor, mortal.
Player Response
Result
And, if I were to threaten your lord, I suppose that would constitute an offense against your honor, supposing also that you are oathsworn to Lord Dagon?
Then I fear I am bound to offend you, my lady. I bid you good day.
END &DarkEnemy
A difficult matter, my lady. You see, I desire something from your lord that he may not wish to grant me. I desire my safety, and the safety of my friend, and our return to Tamriel.
I know my lord's mind. I believe he might be content to spare your life and the life of your companion, on the condition that you both bind yourselves to him by solemn oaths. The harm you have done him grieves him, but not so greatly as to blind him to your value as a faithful servant. On the other hand, I am sure he would in no way consider your return to Tamriel.
Player Response
Result
I cannot consider service to Lord Dagon, and would not consider forsaking my native land. I thank you for your words, but I doubt that our affairs can be settled except a contest of arms. Good day.
END &DarkEnemy
So, if my companion and I were to swear oaths to Dagon's service, our lives would be spared?
None whatsoever. Humble creatures like you have no power to bind great lords to their oaths. But consider: great lords become great lords by attracting to themselves retainers of the highest quality. You and your companion have proven yourselves worthy.
Player Response
Result
So we have no guarantees at all. We must simply trust to the generosity, and wise judgement, of Lord Dagon.
If you were to deal in good faith, then it would only be in my lord's best interests to preserve you, and even encourage you with gifts and status if such were your just desserts. I have recognized your merits, and I have my lord's ear. My recommendations would carry great weight with him.
Player Response
Result
You have given me much to consider. Thank you, and goodbye.
At one point in the game's development, Si'ess was set to appear again in Level 5, after the Apprentice had successfully killed Herne Egahirn. The player would need to ring the bell within the Donelon Belltower to summon her and allow the Apprentice's passage to the Havok Wellhead.
Success to the Huntsman whose Race is Won. Sweet rest to the Hare whose race is done. The Victor calls the View to the Kill, and calls the next Hunt, if that be his Will.
Player Response
Result
I renounce the Hunt and its rewards. I curse your Hunt, and mock your Law.
Of course. And under the Law, a fair and just Hunt. Hark, forward, the Innocent Hare. The Hunt is up, and the Game is afoot. Now, excuse me while I give notice to the Hares. By the Law, you may not participate in this Hunt, mortal. Leave this island, if you can, but trouble me no more with your affairs.
Player Response
Result
Oh, by the way? Could you have the heads mounted and framed? Thanks awfully. Goodbye.
END Teleport_0
Pardon me, Winged One. I did not mean to be a burden. With your permission, I depart.
The Hunt may not be Called upon the Master of the Hunt, mortal. I declare your Call foul, and deny the Hunt. You may leave me. Now. While you still enjoy the Sanctuary of the Victor. But touch me, and you forsake your immunity. And know this, mortal. Then I will hunt you down and teach you respect for the Law and your betters.
Player Response
Result
Oh, goodies. Help after school. You're SO generous with your time and attentions. Until then?
END Teleport_0
You know, threats like that are just IRRESISTIBLE. So. If I touch you, even just a little bit, you are going to Teach Me a Lesson. Oh, may the Blessed Powers give me restraint.
You have missed your calling, mortal. You show an unexpected and not-altogether-welcome gift for comedy. You may not Hunt Lord Dagon, for he may not be summoned upon the grounds of this Hunt by the likes of you. I rule your Call foul, and deny the Hunt. You may leave me. Now. While you still enjoy the Sanctuary of the Victor. But touch me, and you forsake your immunity. And know this, mortal. Then I will hunt you down and teach your respect for the Law and your betters.
Player Response
Result
Oh, well. I suppose if Lord Dagon will not come to the Hunt, the Hunt must come to him. And perhaps I may see you there, too, Dark Lady? Until then.
END Teleport_0
I bet Lord Dagon is just a big scairdy cat. Sissy britches. Hiding behind the big flying lady's skirts. Ehr. So to speak. No offense, but can't your Lord afford to outfit his minions? Isn't it chilly soaring around in the nude? Bye, now.
How interesting. I wondered what might be the source of your courage, your power, your invincibility. And now I know. Your gift is madness. The greatest antagonists are either absolutely competent, or absolutely mad. I judge your Hunt fair and just under the Law. Hark, forward, the Innocent Hare. The Hunt is up, and the Game is afoot. Flee, mad, wretched mortal, and give us good sport.
Although she is simply referred to as Dark Seducer in-game, her name is revealed in page 148 of the Battlespire Athenaeum.
While her reappearance in the last level is not explicitly mentioned in-game, a page on the bethsoft.com website around the game's release showcased a section on the Dark Seducer which includes the description of her being Mehrunes Dagon's personal lover, bodyguard, and additionally details voice lines that are shared between both of Si'ess' appearances.