I've put together what I think is a pretty good model for randomly generated character development. In addition to their personality traits and relationship type, NPCs also have a motivation and an attitude towards the PC. These two attributes can be advanced through a series of values.
Today I put together a simple program to examine the core story components and tell me how many components there are for each possible state of the enemy NPC. Here's the chart it produced:
Core Story Enemy Chardev
--- mer pro com ggd see rev cha nih
--- 003 - 001 - - - 001 - -
nme 002 002 002 002 002 002 002 002 002
jr_ 004 001 002 001 001 001 002 001 001
sr_ 002 001 - - - - 001 - -
ant - - - - - - - - -
tha - - - - - - - - -
sec - - - - - - - - -
equ 002 - 001 001 001 - - - -
env 003 001 - 001 - - 001 - -
dis - - - - - - - - -
adm 001 - - - - - - - -
pch - - - - - - - - -
hat 002 - - 001 - 001 001 - -
mut 001 - - - - - 001 - -
obs 001 - - - - - 001 - 001
The motivations are listed along the top, the attitudes down the side. The number indicates how many plots are available for a core story enemy with this attitude/motivation combo. There are more attitudes than motivations because that aspect of character development is meant to be more flexible. Here's the key for the different values:
Motivation
--- Unknown quantity
mer Mercenary. NPC is in it for the money.
pro Professional. NPC seeks his personal best.
com Competitor. NPC seeks to be better than others.
ggd Greater Good. NPC believers self to be working for greater good.
see Seeker. The NPC still hasn't found what they're looking for.
rev Revenge.
cha Change. The NPC decided to change their current situation.
nih Nihilism. The NPC seeks destruction.
Attitude
--- Unknown quantity
nme NPC hasn't met the PC yet
jr_ NPC is PC's junior/subordinate/student
sr_ NPC is PC's senior/superior/mentor
ant NPC feels antagonistic towards the PC
tha NPC feels thankful to the PC
sec NPC is keeping a secret from the PC
equ NPC respects the PC as an equal
dis NPC has lost respect for the PC
env NPC envies the PC
adm NPC admires the PC
pch PC has a reason to hate the NPC
hat NPC has a reason to hate the PC
mut The PC and NPC have reasons to hate one another mutually
obs NPC obsessed with the PC
Note that attitude and motivation can only be changed to a value lower down on the list. In general only one of either motivation or attitude will be changed at once. Also note that the current list was created mainly to deal with the core story enemy- more attitudes and motivations will probably get added as lancemate character development gets fleshed out.
Ideally, all combos should have at least one associated plot since an empty cel is a deadend waiting to happen. Even though some combinations are impossible to generate (AFAIK, there is no way possible to get a Thankful Nihilist), the complexity of the story generator means that I don't have an easy way of telling which ones are definitely impossible. For the time being I'll just patch the deadends as they occur, trying to shepherd stray antagonists back to one of the rich patches on the chart.
One of the good things about this graph is that I can use it as a guide for creating new content. When adding a new plot, I can check to make sure that the changes it make won't deadend the story. I can also look for bare patches and add more content there, which should help different enemies to seem like different characters (at the moment, every core story enemy develops about the same way). It won't be necessary to create individual plots for each combo since there's often overlap (for instance, a plot might require that your enemy's motivation is Mercenary, but the attitude can be one of a wide range).
Something this chart doesn't tell me is where the enemy NPC is likely to end up- certain combos are probably more common than others, and those spots should get more content than the combos which show up only occasionally.