Every Factions arc begins with the community selecting the factions that will face off in a dispute before the League of Legends. In preparation for that, the roster review team (led by Summoner Theoretica) has devoted considerable time to hammering out Champion rosters for each faction. This is not an easy task: Champions are fickle creatures, often with complicated backstories and (to put it mildly, in some cases—looking at you, Shurima) complicated relationships with one another. But I think they’ve done an admirable job.
Links
- Draft rosters
- Google Form for submitting suggestions
- Factions forum thread
- Reddit thread
- Boards thread
How were these rosters created?
To briefly explain the three categories of Champion:
- Core. Their absence would be noticed. Factions generally begin with all of their Core Champions. (Example: Garen on Demacia. The reasons are clear.)
- Secondary. Their presence is uncontroversial. Factions recruit all their Secondaries over the course of the arc, but they decide on the order. (Example: Ahri on Ionia. She’s pure “fantasy Asia”, and she lives in Ionia, but she’s not defined by her relation to Ionia.)
- Tertiary. Their presence is controversial, but plausible. Tertiaries add a bit of a final twist to a faction’s roster. (Example: Alistar for Demacia, with a tenuous but plausible lore connection.)
The next step is to open this up for broader community discussion. The roster review team has created a forum thread for this purpose.
You are encouraged to review the draft rosters and make any suggestions you may have on this thread.
If you prefer, you can also submit comments through this form, particularly where you strongly disagree with a placement:
While I’m at it, now is also a good time to pitch some arc ideas here.
—CupcakeTrap
Caitlyn, you monster.
FACTIONS 
You spelled “Disputed” wrong. That or “Disrupted”.
…well, I feel stupid. Thank you! Fixed.