Not an expert, but The Magisterium was ironically the easiest I've found to go full lich. Although it's incredibly difficult to get your ruler to live long enough to achieve lichdom even for a magic centered nation. And there weren't any missions I found that became unachievable due to becoming a lich king.

There are three different tags in 1444 that do this in their mission tree with differing flavors. You have Chaingrasper in the Eastern Serpentspine where you become an order obsessed goblin lich dictator, Gemradcurt in north Aelantir where you become the undying lady of the eternal ice in sway to the fay of the eternal winter, and then the Order of the Iron Sceptre in escann, a group of mage supremacists disgruntled with the current order who go on to form Esthil, a nation run by necromancers that if they succeed will form the Black Demesne, which is an experience.

引用自 Typespin：

There are three different tags in 1444 that do this in their mission tree with differing flavors. You have Chaingrasper in the Eastern Serpentspine where you become an order obsessed goblin lich dictator, Gemradcurt in north Aelantir where you become the undying lady of the eternal ice in sway to the fay of the eternal winter, and then the Order of the Iron Sceptre in escann, a group of mage supremacists disgruntled with the current order who go on to form Esthil, a nation run by necromancers that if they succeed will form the Black Demesne, which is an experience.

Thank you, gonna check those out!

I would like to add DO NOT NEGLECT DIVINATION SCHOOL

upon getting renowned you are able to cast a spell that will give you a large whack to your research to upgrade your mage school tier i think 250 that can be cast with a cooldown of 1 year very very useful if you plan on mastering several schools. combined with regular event triggers you can get your legendary much much faster

A bit older post, I know. But lich playthrough with undead armies is very fun. I like factions that have some kind of twist in their military: Like very fast but squishy harpy armies without cavalry, centaurs, cannondwarves. And and the undead are one of them too: no shortage of manpower, huge armies but slow troops (navy is handy).

On the other hand, I wish that you could change your provinces to "undead culture". But on the other hand, I understand why it's not possible.

There is also another Adventurer faction in escann that goes to lichdom, but lot later than Esthil... New Wanderer faction they also build 3 wonders into area.

For magic there is also Steward of Sorrow which has a reform "Taste of Magic" (3 other reforms need to be passed first) giving +50% average life span and Rulers and Heirs have a higher chance to become powerful mages. They will learn 1 additional school of magic. Stewards also has a decree giving +20% magic experience.

Stewards of Sorrow also use Hedonism (instead of Legitimacy etc) which gives +25% average lifespan at 100

You can also claim the Stewardship as a country with elves to get elves with +50% to +75% lifespan which should give you plenty of time to become a lich. I did it with Jaddari (they are very expansionist having lots of missions giving claims. Including areas up to and including the Steward of Sorrow start location)

Yeah Undead armies are very different and cool. They are amazing at sieging in that they mostly ignore attrition and have so much manpower which also make them great at rushing down forts by throwing military power (breach) and manpower (assault)