Ahoy! So I've got the new version finished-- we've got 4 more leaders this time around: 2 Svartalfar, 1 Luchuirp, and 1 Grigori. I've also beefed up a few of the minor leaders who sit unhappily beside major leaders with the Adaptive trait-- the two Kuriotates minors are getting free mobility for their centaurs, and Kane now gets +3 happiness from his palace, to make them actually useful alternatives to the major leaders. Let me know if you think I overdid it.
Anyway, the new leaders:
First! A Svart leader by the name of Shirc Voljah, who gets immediate retaliation on civilizations who declare war on him, by setting an all-comers bounty of 10 gold on each of their units' heads for a period of time. This makes his worldspell a bit more useful in a multiplayer context, since it means that enemies will be much more reluctant to extract vengeance for Hidden Nationality shenanigans. Plus, giving rivals incentive to declare war on your newfound nemesis can only be a good thing! (Non-multiplayer, this causes the unit to appear weaker to computer-controlled civs, so it still makes them more likely to declare war on your attacker. And, of course, you get money from everything you kill yourself.)

Second! Another Svart leader by the name of Lugatorix, who has the Dominion trait, preventing hell terrain from spreading into Svartalfar lands-- regardless of religion or alignment. What fun! Especially in the late game or if you feel like going AV. Ashen Veil elves? WHAT MADNESS IS THIS.

Third! A Grigori leader whose Great Commanders give fairly muscular bonuses to their Heroes via the Party Leader promotion. Hey, it had to happen someday-- what's a party, after all, without a Cloud or a Squall to lead them?

Fourth! A Luchuirp leader named Tempras, whose golems gain cumulative bonuses for fighting in terrain they've fought in before (3% each time). So, a given golem who's fought in Desert three times gets a +9% to fighting in desert from then on, and it only goes up from there!
As always, bug reports, balance commentary, general feedback, and wild allegations of criminality are greatly encouraged. The new patch has been posted in the OP, where the old one was.
So anyway! Now I'm thinking of having the next patch be mostly of establishing lore for these various minor/emergent leaders. The only ones I've got anything for are Caluxus and the new Shirc Volja, so really, any short snippets are appreciated for any leaders you might care to do. Or long snippets, whatever. Although I'm still quite open to trait ideas!