I'm not posting this in Community Creations for two main reasons:

1. I think this qualifies as a thread about various Champions' themes and relations to Piltover. It's a bit speculative from a canon perspective, but so far as I can tell, most of what we do on this board is speculative anyway. (Insert "dark and mysterious past" joke here.)
2. Nobody reads Community Creations. That's something I'd love to change, but in the short-term, that's the reality.

So, background. Factions is a community game mode based around…you know what, I've typed that out so many times that I'm just going to stop there, and instead say: in Factions, we have faction versus faction matches (e.g. Demacia versus Noxus), and each faction gets to choose from Champions affiliated with that faction. Factions start off with smaller default rosters made up of the Champions with the strongest connections, but Summoners can also recruit more Champions as the arc progresses, which both adds in some story developments and brings in a meta-strategy element.

Tiers of Champions

Here's the tl;dr on Champion categorization:

• Core. Champions whose absence from the roster would be downright bizarre, given how strongly connected they are to the faction. Examples would include Garen for Demacia. Factions start each arc with at least their full Core list.
• Secondary. Champions whose presence on the roster would be largely unobjectionable. These Champions are easy to recruit, and factions may also start with some of them to pad out their lineup.
• Tertiary. Champions who have some connection to the faction, but are kind of weird or out of place. These are "expensive" pickups, consuming two pickup slots whereas Secondaries consume only one. In-universe, recruiting them often involves pulling strings with the League, making them special promises, tilting the faction's objectives to satisfy them, and so on.

There are presumably in-universe rules for who gets to recruit which Champions. We purposely leave that kind of vague, so as to avoid the need for some massive exegesis of League Champion selection law. Really, it's more of an out-of-universe question of how well the Champions fit together.

Factors

And here's the quick version of the main factors we consider:

• Story. The Champion's written story. This includes both Riot lore and Factions lore. A Core Champion should have a really powerful Story connection. (e.g. Jarvan is the crown prince.) A Secondary needs to have at least a moderate connection. (e.g. Ahri lives in Ionia, even if she cares more about eating/not eating livers than helping Karma with anything.) A Tertiary ideally has at least a teeeeensy bit of Story connection. (e.g. there's some throwaway mention of Shaco having lots of fans in Noxus.)
• Theme/Feel. The Champion's overall tone. This might include their visual appearance, their VO, or just the tropes they invoke. A classic Secondary-level combination is a dash of Story and a big dose of Theme, as with Ahri: even if her written backstory had her as being from the Freljord or something, she's a freaking kitsune (or the Korean equivalent) and obviously belongs with fantasy Asia. Leona is arguably an example of a Secondary based on Theme, for Demacia: though her Story connection is weak, she's a knight in shining armor type of character who fits right in.
• Gameplay. Part of the fun of Factions is that factions tend to develop unique playstyles. For example, Demacia is known for its aggressive all-in teamfight that involves everyone pushing R and shouting DEMACIA! really loudly. A Champion gets some bonus points if they enhance this playstyle, or meet some other Gameplay objective, like providing a lower-IP option for ADC. Note that filling in a gap or weakness is not really a Gameplay strong point; factions get their unique identities in part from their limited rosters. Necessity is the mother of invention and all that.

So those are the main factors.

Piltover

So, Piltover. Piltover doesn't have a lot of Champions. It just doesn't. Here's what we have so far:

Current Roster These are the Champions they already have. Most are Core; it doesn't really matter, though. The current roster is locked in, for better or worse. Just providing it for context.

Secondary These are easily recruitable Champions for Piltover. Definitely looking for suggestions here.

Tertiary These are "reach" options.

I actually think there's a case for Tristana being Secondary, given her use of tech. Veigar is there only as a hostile to Noxus, another faction in this arc. Lux is there for that reason as well, although she also has a few other factors I won't get into.

So. Any ideas? Particularly looking for more Champions to add to their list of options. I'm trying to give each faction at least five. Piltover is also in a rough spot balance-wise, and could use a hand.

Some Ideas

• Story (weak). Nautilus has some questions about his origins or whatever. Piltover has science that could help answer those questions.
• Theme (moderate). As a big old-fashioned diving suit, he does have a bit of a Piltover look to him.
• Gameplay (weak). He's not really a poke champ.

• Story (weak). If anything, you'd think Nidalee would dislike the City of "Progress". On the other hand, Piltover is a champion of "clean" technology, and Piltover sure is a lot better than Zaun in that regard.
• Theme (negative). She's a primal huntress. They're a clockwork-steampunk-technological civilization. Together, they fight crime. They clash horribly.
• Gameplay (strong). On the plus side, she's a great ("great") poke champ, and Piltover's traditional strategy is poke-heavy.