[Twan]

Communion is not the issue, in end game destroying (or sometimes enslaving) entire armies in round one is possible with any nation having a good gem income.

Without communion you just need more boosters, some empowerements at worse, to cast the same kind of spells (undead mastery is a spell any nation can use once they have one D7 mage able to summon tartarians = usually all competitors in endgame ; and common tartarians paths allow anyone able to summon them to use rain of stones or earthquakes in round one ; storm, fog warriors can be cast by air nations boosted mages, air queens, seraphs, some tartarians, etc ; with astral nations like Rlyeh, Pythium or Arco you can have some S8 mages (S5 + 3 boosters) able to cast master enslave out of communion ; mine rare S5 were just too busy wishing on an alteration bonus site), etc....

There is no preset libraries out of central plain it's a fact (and I didn't found one in this game out of the one preset in a city of the plain on my fronteer with Caelum). I did found a temple of the magus early and an animists hut near my capitol but my number of indie mages random sites was rather small considering the size of my realm. About one random mage site (library being one of the most common) for 10 full searched provinces is a normal medium number in any dominions game.

In fact I've mostly won because of the war between Caelum and you which helped me a lot in early game (when I was rather weak with the low income from my luck/turmoil scales), I've been lucky to have on one side a neighbour at war and on the other Ulm who was very slow to reach the plain, so I could expand quietly. Once you signed peace Caelum attacked me to take his part of the plain but it was too late, I had enslave mind to catch more mammoths in each fight than I was losing troops, and he abandonned fast (I could have had far more difficulties against you as Man don't have the mammoth MR problem, but you prefered an alliance with me to another war, allowing me to take the isle and expand in caves, charming some big monsters, instead of having to defend my conquests).

I wasn't at all expecting a so fast expansion, my build was a very long term one with a dormant mother of clams (finally I've not really clam hoarded, I just made a dozen of them then used my pretender to charm beasts or GoR things ; I only had a huge gem income in the very last turns, once I had empowered and equiped two mages to wish for gems on an alteration 20 site) and growth 3 (not a very good scale for a 60 turns game).

After Caelum I've chosen to fight Machaka to add enslaved hunter spiders to my forces (and to help Ct'is as I wanted to have a death nation trade partneer). Fighting davidd was harder than expected due to all his elemental royalty, immortal wraithlords and summoned troops, and the earth attack spells he was casting each turn, it ended in a stalemate where I could win in defense only, and using a lot of mages. I could have been defeated with Ermor, Rlyeh or you helping him at this point. But the only nation who tried to do something against me before the very last turns was Ulm, and if his hundreds of spies were annoying they aren't a big problem for a mind hunting nation. Ermor could have attacked the isle with say 200 undeads a turn since 15 turns, to make my mages on the isle waste their gems each time (and kill themselves with friendly fire), and Man could have cut my income by half taking our border provinces and the undefended old caelum realm.

Even in late game (3 turns ago, when I was still patrolling it with most of my mages out of the fort) an agreement between 2 or 3 nations to attack the isle at the same time could have mean defeat for me as all gems would have been used in the first fight (of course only the last attacker would have survived, but then you had 36 more turns before his victory).

In conclusion no reason to blame communions, first round casting, your nation or the victory condition. With this kind of settings, ganging against who threaten to win (and far sooner than in the last minute) is an absolute need. I simply shouldn't still have all these mages, units and income to defend the isle after 34 turns on it.