Tell me, how do the cards Wild Energy, Love of Chaos, Power and Sacrifice, Summon - Tristayne(from the deck Unstable Forces), Call of the Ravens and Blood rage on Khorayt?

I think you're going to have to be more specific with your question.

What about these effects?

I can tell you that Summon Tristayne has no valid interaction with this dragon. Summon agent cards can only be used on open groups.

Does Khorayt receive damage from Power and Sacrifice or Call of Ravens? Can I play these cards on him? Does the servant appear on the field? Can Khorayt be defeated by Love of Chaos, Wild Energy, Blood rage?

From the CRRG::

Khorayt is considered to be a monster controlled by the
overlord in respect to anything not explicitly specified in
the quest description.

Since Khorayt can only be dealt damage by Sir Alric wielding the Duskblade, then I'd say if you used the Call of Ravens on him you'd be able to get Ravens 'free of charge' as Khorayt cannot suffer hearts as a consequence of creating the Raven.

Regarding Blood Rage - I'd say you can use it on Khorayt to gain the bonus attacks, however, Khorayt would not be defeated afterwards. Not only does it go against the spirit of the quest, I'd say you cannot auto-defeat a target that requires a quest-specific effect to damage.

With respect to Tristayne's plot deck:

I'd say you could not use Power and Sacrifice as it says that the target 'may suffer' hearts to deal more damage. I'd argue that since Khorayt cannot suffer hearts from this source, you cannot use any effects that require the suffering of hearts to activate. This is how voluntarily suffering fatigue works, after all.

As for Wild Energy, I think you can use the card to grant surges, but Khorayt is not defeated if you fail to deal damage.

Finally, I'd say you cannot use "Love of Chaos" on Khorayt. It requires that you defeat a monster to trigger the card's effect and you can't defeat the dragon except via Alric.

New info from Nathan Hajek.

Nice.

I'm hoping this ruling from Nathan will extend to more 'special 'monsters, such as Shadowkeeper Juliden in Juliden's Keep (Mists of Bilehall). She cannot be defeated, cannot suffer conditions, cannot suffer hearts and has no defense dice or health pool.

However, by RAW she can still be targeted by plot cards and Overlord cards such as Call of the Ravens to summon ravens for 'free'. Its pretty cheezy and I think goes against the spirit of the quest. A formal ruling disallowing it would be nice though.

She doesn't even have attack dice. In my view that quest really should not have made her a monster at all - just a generic figure that activates once per Overlord turn and is controlled by the Overlord.