Originally Posted by
Magical Mudcrab
Can you clarify what you mean by "plot magic from Frostmourne", as this seems to be in direct opposition to how the fight is described in Arthas: Rise of the Lich King? In most media, the connection between Arthas and Frostmourne is considered special, and I don't recall Frostmourne doing anything on its own. Illidan lost because he left himself open and there's nothing more to say. Arrogance is a weakness, and if you are beaten because of it you don't get to fall back on arguments of strength (i.e.: you can be as strong as you want, but if you have a character flaw that impacts your ability to win fights, you don't get to discount those losses).
That said, this whole rabbit hole that you guys have gone down is entirely pointless. Comparing Arthas as he arrives at Icecrown to Illidan doesn't even accurately represent their current standing. By all metrics, Illidan was a better fighter than Arthas during that encounter, with the equalizing factor being character flaws that Illidan had. However, when comparing the Arthas being talked about (i.e.: Lich King Arthas) and Illidan, the argument basically ends when you point out that the same people who handily defeated Illidan were immediately and without recourse killed outright by the Lich King. Illidan as we saw him in Black Temple, and probably as he was in Legion since I don't think he got any power amplification, is substantially weaker than the Lich King Arthas and is not going to be a favorable metric when comparing "power level".
That said, people need to keep in mind that Illidan vs. Arthas has no bearing on this thread. We already know that Mannoroth is likely substantially stronger than Illidan and is a bad measuring stick in this case. Looking at the Well of Eternity dungeon, Mannoroth fought Illidan, Tyrande, and several heroes who would go on to kill Deathwing while only receiving meager help from some fodder demons, and did so while controlling the magic of the Well of Eternity by himself to keep the Burning Legion's portal open, with our "win" condition there is just momentarily breaking his concentration. It bears repeating that Mannoroth, while in the midst of controlling the magic of Azeroth to maintain one of the most powerful portals to ever exist in the Warcraft universe, one which Sargeras himself could travel through, was still capable of fighting two of the most powerful heroes in Warcraft and a handful of the most influential adventurers to ever exist and all we managed to do was break his concentration. We can further this by pointing to Magtheridon and Azgoth, two Pit Lords who are substantially below Mannoroth in rank (implying they are also weaker), and Illidan was unable to deal with either of these Pit Lords by himself (Azgoth was even going to kill Illidan before Kor'vas saved him). But we then get to the problem where Mannoroth is constantly treated as a joke by Blizzard, and is killed off quickly and is portrayed as almost being trivial to deal with ("lmao, big burny boy killed by one angry green lad").
Mannoroth should, without a doubt, take this fight easily, but it's going to be hard to convince players of this.