And now, a few thoughts.
First, I had a really good time with this. I didn't really expect to win, and I honestly think I shouldn't have. In some respects this was a diplomatic victory, but in others it was more a victory born of others' failed diplomacy.
Starting with the draft, I selected Illen almost on a whim - as the last player in the draft, things were starting to get sparse by the time the 18th nation was chosen - if I were to do this again, I'd much prefer to do the draft as a round-robin so the same players wouldn't end up picking last each round. As it was, by the time I picked Illen, all my other preferences were gone. I'd wanted a reanimation nation, and the good ones of those were gone. Or I wanted a flying nation, but the most interesting ones there were snapped up. At the very least, I wanted a nation with Astral access, but pickings were even getting slim there, though I could have found one with reasonable troops if that had been my highest priority. So Illen was far from my first pick.
Having said this, there were a few things that drew me to them. It certainly wasn't their sacreds; I didn't recruit a single Molten Templar the entire game. OTOH, knowing that I'd not miss them gave me the freedom to ignore my bless, and take an S9 Fountain to shore up my absolute lack of Astral. Additionally, national mages ignored Drain, so I could use that as an additional source of points. Illen suffered greatly from its lack of diversity - as anyone who fought them knows, you got to get hit with lots of fire but not much else. However, they had fairly cheap F3s they could recruit everywhere, and 40g F1 drain-immune labrats - once I hit Cons-6, they could forge their own Lantern on recruitment and triple their research. Additionally, there were slow-recruit FN2.1[FAEN] mages to help with diversity, but they were a minor factor in my choice. All the serious diversity in the nation was in the capital with its F3.1?[FADB] mages, who were also slow-to-recruit. So magic-wise, I could get minor access to every path but Water and Astral, and there was a hero who could potentially give W1. This gave me a strong potential after the early game, but it would run into difficulty well before the late game. Fire has a dubious endgame, but it's not useless, so if I could survive the midgame I could hope to regain some of my early potential.
Outside of the very double-edged mage selection, Illen had three major appeals. First, they had amazingly good chaff in the form of the Wardancers - low-gold, low-resource recruit-in-any-fort DW bersekering lizards. Those last points were important because it meant their ringmail coupled with their scales to turn them from light infantry into very solid medium infantry. They could be recruited en masse, and were actually surprisingly dangerous - I knew they would be decent troops, but I recruited almost nothing else after the first 40 turns barring pure chaff.
Second, there were the assassins. After 4.04 I was convinced that assassins on D nations are unbalanced, and I still am. My expansion drive was a mix of bands of Volcano Followers (which were my ridiculously-nice but ridiculously fragile cap-only elite light infantry) and small numbers of skelliespam assassins, and every campaign I fought included opportunistic assassins picking off stray troop mules or siphoning troops and gems away to protect mages. They weren't decisive in any war but the first one, but they were by my estimation a serious nuisance the whole game.
Lastly, and in the end most significantly, Illen has H3 mages (which were cap-only, alas) and blood sacrifice. This was actually what made me decide to play Illen. I'd never tried a blood-sac nation in MP before, and I really wanted to see how it would play out. I had no serious notion of using Domkill to dominate, but I figured being able to push my dominion would be good for defense if nothing else. The fact that I also had stealthy H2s made me take this notion more seriously than I otherwise would have, and in the end with good cause. I never had a blood economy to rival Samarir or - Heaven help me - Damerkot, but by the end of the fame I had 7 or 8 provinces with two SDR-equipped hunters pulling in a total of around 100 slaves per turn. In the end, without heavy empowering I really didn't have a lot else I could do with my slaves, as my national mages were rarely more than B1, and when they weren't, they rarely had the crosspaths to do more than summon Bone Fiends.
I fought my first war of necessity, as Midmatia was battering down my capital's candles with their pretender and higher starting domscore... with only one water province between our capitals. While I overran my neighbor surprisingly quickly, that should have been the end of me. Between my aggressive expansion and early war, I took a lead in size that I never really relinquished. More significantly, three of my four neighbors chose to invade me. It was an understandable reaction, though I had trouble appreciating just how understandable it was until much later when I got access to mundane score graphs [aside: I never see those sites, but this game I had two of them]. However, it was poorly executed. Deathig made a full-scale invasion and lost two of its three initial armies in the process. We'd continue to raid and have overlapping borders for most of the game, but we never actually had more than a couple of serious battles. For the most part, I knew that their grand communions would eat small armies, and take any army big enough to hurt them out when they died. For their part, I ran a number of test battles, and I'm pretty sure I could have taken out the Grand Communion... it would have cost me half my mages and 2/3s my armies, though, and I needed those to sit idly on the border with Lisassa. Much to Dheathig's consternation, both Dousheim and Lisassa were content to let Deathig do the heavy lifting while they leisurely picked at my borders. I threw thin blue lines in front of them, and made it clear that any invader would pay dearly, but all I could do was slow them down. This was especially true of Doushiem. Every test game I played, Dousheim was the bane of me until I could get massive hordes of mages to counter their superior troops, and the few times we fought in 410 it was likewise true. If Dheathig, Lisassa, and Dousheim had coordinated their efforts, I'd've been the second player gone.
As it was, Samarir's paper took out Dousheim's rock in a way that made my scissors look quite dull indeed. Lisassa and I traded a few armies on our border, but it was a stable border. The one time they made a heavy press I managed to ratchet up the cost of breaking down my border-fort's gates by deploying 6 Bane Venom Charms inside its overcrowded walls to the point where the seiging force turned around and went home. They should have pushed on to my capital next door, to be honest. Shortly after (or before?) that I made peace with Dheathig and we jointly attacked Agor, and from that point(-ish) forward I was never seriously threatened within my borders. Sure, at the end Damerkot was cutting through my defenses all but effortlessly, with everything I threw at their armies dying, but by then it was too late for anything but a throne victory to stop me.
There were a few diplomatic coups on my part, but mostly I survived and thrived when I shouldn't have because I made it expensive to attack me, and endlessly pointed out the softer targets elsewhere. Illen was by some measures the weakest nation on the map for much of the game. I had tepid troops, broad but painfully shallow diversity, and a horrid geographic position (seriously, that lake is just awful). Up until the end I didn't really feel like I could defeat armies in the field without losing an army in the process, and not even necessarily then. OTOH, by the end I was pushing ~140+ dominion checks per turn, so tactical concerns like lost battles weren't so much of an issue...
Oh, and if anyone wants a look-see at the endstate, or is curious how things looked at any point in the game (I had an excellent scout network), here's all but maybe one of my turns:
I say all but one because I'm pretty sure I didn't archive one turn between 10 and 30 because my count didn't agree with Llamaserver's, but I could never bring myself to go back and figure out which one I missed.