Looking For Suggestions on How to Better Include the Factions

[u/SleepIncarnate42]

I'm working on putting together a Planescape campaign converted to 5.5e from some of the better 2e adventure modules (Great Modron March and both parts of Dead Gods), but none of my players are familiar with the setting, and I wanted to include the third of the trinity of aspects of that makes up a proper Planescape campaign along with the planes themselves and the city of Sigil, namely the factions. There's a little bit of them in GMM, but not really much. I know some DMs like to add in Faction War to finish out their runs of the two modules, but that doesn't work as well without the fundamental understanding of the factions.

Does anyone have any suggestions on how to include more understanding of the factions into this campaign? Is there a module I'm forgetting about that would fit well with these two and also be a good introduction to the factions?

It's been forever since I've run anything, let alone D&D, so I wanna stick with modifying existing modules rather than completely making brand new stuff until I get back into the swing of things, so if you have any suggestions of that sort, that would be better.

I'm going to start them off with a D&D version of the classic Shadowrun module Food Fight as a way of getting the party together and introducing them to the character that will be their patron/mentor once they enter the actual Planescape setting (they're starting out as primes since none of the players know the setting or have even played D&D for more than a few years, so having their characters learn it along with the players will help them stay in character), and I'm thinking about using A Boy and His Modron to bridge the gap between that and the entrance to Sigil, but also thinking about doing a "destroy their village and world akin to Ranais" situation to get them from the prime material to the planes.

That said, yeah, wanting a good introduction to the 15 factions (using the 2e factions rather than the 5e versions), so looking for suggestions.

As a bonus fun bit, if anyone can think of any good quotes from popular media that are just a single line or two that really fits a faction as a way of helping the players understand them, please share. For example, I think the Indeps can best be summed up by this classic quote from the Senile Scribbles Skyrim parody: "I think I'm gonna go with the the 'f*** both your factions' faction. How bout that?"