Kreegan
The Kreegans are a race of technologically advanced, hive-like humanoids who are one of the main enemies of the Ancients. They have taken over Eeofol after invading the planet Enroth. Inferno's lineup is composed of demonic creatures bred and summoned by them, with Kreegans themselves being represented by Devils and Arch Devils.
Kreegan reference 
The following is a short story that was written by a New World Computing employee and published on the now-defunct fansite "The Nether Gods".
NOTE: Before you read this, I might want to point out that the Professor has sometimes interrupted the letter making it hard to tell who is speaking, so I have posted Xanthor's words in the lighter blue.
"Good afternoon! I discovered that earlier today the University received a letter from Xanthor. Since I knew that you would want to hear word of him, I shall read his letter to you.
*ahem*
"To the Staff and Students of the University of Erathia…" blah, blah, blah, "…August 6th, 1164."
"Colleagues." He's always so formal, isn't he?
"I know my journey has barely begun, but I felt it would be a good idea to keep you posted of my progress on a regular basis, even if at times it seems like nothing is happening. In the two weeks since leaving the University, I have seen little in the way of the excitement that Prof. Finch and I encountered in Stillbog."
"We continue to travel to the northeast, toward AvLee and the Contested Lands. The weather has been good, and looks to stay that way, though as we travel farther to the north at this time of year we should definitely find some cooler climes. A Knight by the name of Desslock is our guide to the Contested Lands. Beyond that I understand that an experienced Ranger will be leading us through the forests. The eastern countryside of the kingdom is beautiful. Gentle, rolling hills and quiet streams make for a pleasant journey, and it's easy on the eyes as well. I would like to thank you all again for allowing me to tour the world!"
"Ah, here is where things get curious."
"But there is a reason I chose to write to you today. Last night we stayed at an inn in the town of Whitestone. Strange thing about this town, we didn't actually *see* a white stone anywhere. In fact, most of the buildings weren't built of stone at all! Anyway, we met a messenger who had stopped there for the night who told us that he was on his way to the capitol. He said that he had not read the letter that he was carrying, but that it was given to him by a commander of the eastern garrison near Eeofol, a volcanic range on the eastern coast of the continent.
Apparently, there had been some sort of battle there. The Erathian guard was not involved, they merely found the site where the battle took place. Actually, the messenger knew very little of the events, only that which he had heard while waiting to receive the letter. If what he heard was true, the battle was between creatures from Eeofol and creatures from the underworld, much like what we saw in Stillbog."
"Since Xanthor doesn't mention it, I should point out for those of you who don't know that the Eeofol range is home to many of the creatures of the Infernos."
"Unfortunately, I have no other information of the incident, but our journey to AvLee should take us near Eeofol. I shall keep my eyes and ears open for any other news."
"Warmest regards, Xanthor.
Well, that's the letter. I shall have to see if I can gather any information from here. Do not worry, there have been no problems from that part of the world in centuries. Xanthor should be safe and sound."
CLARIFICATIONS
"After reading Xanthor's letter yesterday, I realized that there were a few things I should probably clarify. First, let me start with the Infernos. These places of summoning and breeding are only part of Erathia's recent history. You see, approximately three years ago, a race of devils known as the Kreegans mysteriously appeared in Erathia. Several astrologers claim their arrival was signaled by a star that fell from the heavens, crashing into the volcanic Eeofol range where the Kreegans are most prolific.
Shortly after their appearance, they immediately began to attack the nearby settlements. Initially, the only resistance they met were the garrisons of the Contested Lands. The Kreegans moved so quickly that the human cities of Dunwall and Marishen, along with the elven city of Bath'iere, fell before any large force could be brought against them.
Troops from Erathia teamed up with elven armies from AvLee, and together were able to halt the advance of the Kreegans. However, not even the combined might of the two strongest armies in Erathia could secure a victory. As the generals sought a solution, one came from a most unexpected place. The Dungeon Overlords, long-time enemies of Erathia, attacked the Kreegans from their flanks, but rather than destroy the army, they subdued them. The Kreegans, apparently now under the command of the Dungeon Overlords, retreated back to the Eeofol range, where they have remained for nearly all of the last two years.
In that time, new garrisons have been created by both humans and elves alike. Reconstruction of Dunwall has begun, and the armies of Erathia and AvLee have found themselves in several insignificant skirmishes with creatures now bred or summoned within the Eeofol Infernos. More often than not, it is troops of the Dungeon Overlords who step in when the Kreegans seem to get out of hand. The event that Xanthor reported was evidence of that.
With luck, we will one day be able to rid the continent of the scourge of the Kreegans and their allies. However, one must wonder why the Dungeon Overlords, who have never been friendly toward Erathia, did not merely allow the Kreegans to run rampant across the land?
Ah, well, that is a pondering for another time."
DISTURBING LETTER
"Oh dear, I just received a disturbing letter from Xanthor:
"To the Staff and Students…" blah, blah, blah, "…August 14th, 1164."
"Today was very strange indeed, and I fear that if I do not put today's events into writing before turning in, I will wake tomorrow having forgotten much of it. I shall try to remember it all.
"Our travel has been swift. Desslock tells me that we should reach the Contested Lands in as little as another week provided the weather holds. In fact, we're making such good time that this morning when we came upon the town of Claxton, Desslock decided we would spend the day here and leave tomorrow.
"As you know the library in Claxton is one of the most complete outside of the University (not including, of course, the libraries of Bracada), so I decided to spend the afternoon there. I wasn't looking for anything specific, but I did come across several interesting texts, including one highly entertaining novella written about many of the famous personae of Enroth. I'll have to see if I can't get a copy made for the University.
"About mid-afternoon, a slender gentleman entered the room I was in and began casually browsing through the scrolls. He was wearing a long coat of sorts, similar to the clothing of the Bracada Highlands, which seemed odd considering the warm weather. When I inquired, he said something about not having packed enough summer clothes for his journey. I pressed him further (you all know how nosy I can be), and discovered that he was from Silver Cove in Enroth!
"Well, we must have chatted for hours, eventually leaving the library for a nearby tavern, him telling me about Enroth and I about Erathia. I feel I need to report, however, some of the news of Enroth. First, the continent is in chaos. Apparently the armies of Enroth were not nearly as successful of stemming the tide of the Kreegans as the armies of Erathia. According to my friend, King Roland Ironfist marched an army to face the devils and never returned. Between that and the increasing number of natural disasters that have been occurring, many are starting to believe that the Ironfists have lost the 'mandate of heaven,'1 which he explained as 'the divine right to rule.' Hearing some of his tales, I thanked my lucky stars that such occurrences did not happen here in Erathia.
"At one point, my friend began rummaging through his pack that he carried with him, and I noticed a sealed letter marked with the name Zenofex. When I asked him if that was his name, he quickly shoved his belongings back into his pack and said, 'I can't discuss it here. Meet me back at the library in 10 minutes.' With that, he left the tavern.
"Well, you know how easily distracted I get, and tonight was no different. There was a travelling bard at the tavern who was telling a story but seemed to be making it up as he went along. I was enthralled, and as a result I completely lost track of the time.
"Suddenly there was a woman's scream from outside in the street. Everyone in the tavern, myself included, ran outside to see what had happened. It was dark, but we could see that across the street, at an entrance to an alley, a body was lying in a slowly growing pool of blood. The woman who had screamed said that she had seen the man come out of the tavern and cross the street. Just as he got to the alley, a figure wearing a foreigner's longcoat leapt from the alley, slit the man's throat and then just disappeared into the shadows.
"By the time the city guard arrived and managed to clean up the mess, most of us had returned to the tavern, though in a much more somber mood. As I mulled over the murder that had just had just taken place, a patron approached me and asked if I was related to the victim. This of course seemed like a strange question, but I told him I was not related and asked why. 'Because,' he said, 'you look a little bit like he did.' I downed the rest of my wine in a single gulp, then asked for an armed escort back to the inn where we were staying. I then began writing this letter.
"I don't know who this Zenofex person is, but I hope never to see him again, or if this traveler was actually him. I shall be staying a little nearer to Desslock for the next week.
"Until next time, Xanthor."
"I do hope he stays out of trouble. He could have gotten himself killed! Well, you must excuse me, I must see that this letter is sent to the King's palace. The King will certainly want to know of the goings on in Enroth."
-Finch
1 See Might and Magic VI: The Mandate of Heaven.