Mm. Well I already noted that Larsa isn't happening this season, and it's entirely valid to say that there are currently better ranks. Since people want to bring it up, let me explain why Larsa is still a good rank. FF12, much as it got a... mixed reception, was still a pretty major release. The FF series is probably easily the best played series in the DL. It would just seem strange to not have a representation of it here. It's hard to say about FF12 drawing in general, but the same is true of a lot of possible ranks. It's a single FW nom, so the costs of not drawing well are not nearly as bad. Anyway, the mechanics mean that the PC cast is basically out, like FF5. That leaves the temps as having unique abilities and stats and the bosses. However the bosses translate to the DL really badly, so it is just the temps after all. This leaves... Larsa and Reddas. Reddas is kind of boring and gets hit hard by late-game FF12 interpretation. So... Larsa. Luckily Larsa actually has plot and a personality (more than Penelo! About as much as Fran!), so he fits the bill pretty well as an FW rep of the game. And despite Tal's concerns, I'd say he translate to the DL pretty simply - he's a low-damage item-based healer with an infinite sack. There ya go. (Maybe not the most INTERESTING dueler ever, but quite easy to interpret.)
Reponding to Tal's concerns:
Larsa's AI issues are annoying but mostly irrelevant. His Gambits are to attack at high health, toss a Hi-potion at low health (I want to say 40% HP?), and toss an X-Potion at critical health (So his healing is basically always full). In Light this is generally exactly what he wants to do. Admittedly there will be rare times where a "smart" Larsa would fight differently than a dumb one- say, a slow and frail opponent who Larsa 2HKOs, but 2HKOs Larsa back with their attack, and has a low probability of some kind of fatal status attached to the attack (AI Larsa will waste time healing their damage and eventually be statused when he could have just attacked for the kill). This is a downside, but hardly a fatal one.
As for scaling, I think we can just do the sane thing and scale him against what an average party would have. Nobody who's not playing challenge games would fail to get licenses for things like storebought weapons and armor available when he leaves. This would be a bigger problem for Reddas thanks to extremely broken and potentially universal equipment like the Bubble Belt, but not really for Larsa. I guess you can haggle over how much HP Larsa has depending on whether you see everyone in Light Armor and the legality / average of HP+ augments, but it's not the end of the world if one person sees Larsa at .95 PCHP and another at .80 PCHP.