((It's OK. I'm getting an education too, but my class schedule is quite the slacker schedule. =D))
"To answer your question bluntly, no.", Geralt told Galacta Knight, "Hmph, I suppose you can go see this Kil'jaeden now, though, since you don't seem particularly fatigued or hungry. If not, save your pretensions."
Taunos chuckled, "Now, now, I doubt his race functions like us.", Taunos calmly explained, "Actually, this is quite important. You may have noticed I have been casting spells left and right. Unfortunately, this does leave me drained of mana, so I must rest, as well as to avoid fatigue."
Taunos then turned to Spire to answer his question, "Thought you'd never ask. Kil'jaeden is an eredar, like other leaders in the Legion. A corrupted, demonic one, of course. That does make him immortal, but not quite invincible. Archimonde, another powerful demon eredar, was killed at Mt. Hyjal, but only when Malfurion, the great night elf druid, summoned thousands upon thousands of spirits from the surrounding forests, who clung to him and exploded, unleashing far too much disruptive energy for the demon to handle. So actually killing Kil'jaeden is out of the question. We could weaken him to a point where we could banish him, but that's quite the challenge. At the Sunwell, I was with 24 or so blood elves and Forsaken of various callings, but on our side was also the Blue dragonflight. And even then... Anveena sacrificed herself to weaken him. At that point, we could finally banish him."
"Dragonflight?", Geralt asked.
"Yes. Ah, Kalecgos, a blue dragon, had orbs from the blue dragonflight brought in.", Taunos recounted, "Once he empowered them, one of us would transform into a blue dragon for a short period of time. Though very limited in use, using the powers granted by the orbs, we could ward off Kil'jaeden's worst attacks."
"I have this feeling you're going to tell me we won't have any dragons helping us now.", Geralt grimly said.
"No, unfortunately.", Taunos replied, "I wish there was something or somebody helping us. To answer your question, Spire, they have no real weaknesses. Whereas Archimonde was a brutal destroyer, Kil'jaeden has unrivaled cunning and trickery to back up his immense magical prowess."