Rance Quest Magnum (purchase link). I’ve cleared the final story-related question in Magnum, although there’s more content that’s unlocked afterward (mostly difficult fights, and the option to after clearing a few of those, to change to World 2/replay the game at a harder difficulty level. Worlds 2 and 3 are probably strictly for masochists, especially as some of the battles from what I’ve read require immense amounts of levelling up, or are plain impossible to beat. There’s a video on nico with a party including Level 254 Rance, getting absolutely annihilated by the final boss of World 3, on the ??? quest)
Positives: Significantly better story than Quest, ties up all of the loose ends in the original with Crook, the AL Church etc., and fixes balance issues, making the gameplay a highly addictive and enjoyable experience. Magnum offers very good value for an expansion pack, although I think that’s partially to make up for the original game being incomplete.
Negatives: Three significant mistakes, and some smaller errors. The first is that while Magnum is an IF story, there are many events which explain the actions of Crook/role of the AL church and are almost certainly canonical (otherwise the information would just have to be repeated in a latter game), however in other sections, particularly towards the ending, there are definite story contradictions. Particularly for the final quest for each, I think they needed to do it once, incorporating all of the ‘true’ events, as it takes place in the same location for both games, but with very few consistencies between the two.
The second, is that there are too many characters. Even though Magnum does add at least one individual event for all the characters via Quest 134, when you have a party of over 60 characters, but can only use 5 in a battle, a lot of them will only be used very occasionally, or not at all (some characters are unable to learn say high level spells, and others come with significant drawbacks, and quite a few are just very underpowered). Some XP from each battle flows onto the other party members, but it accumulates very slowly, and won’t be enough to make the characters useful without grinding.
The third is something that will never be fixed… NO VOICES.
Edit: Completely forgot about a fourth issue. The game is limited to a single save file, and afaik changing the difficulty level to easy/going to World 2 will overwrite the existing save, as different difficulty levels force you to start the game from scratch. If you want to keep your ‘World 1’ save, you’ll need to artificially back up your save data. While the logic of the single save is understandable, since any failing a quest does not have any consequences, it’s not a very user-friendly design.
These are all relatively small issues. Some of the new side-quests are very well handled, but others are redundant + uninteresting (same goes for several quests in the original too). Certain levels have annoying features such as invisible exit points, that you have to stumble over. Although the balance is generally excellent, I still think the escape skill needs to be toned down and/or removed, as the fastest and safest way of clearing some of the longer and more difficult stages, is to take multiple rangers, give one the skill upgrade that gives a 100% success rate, and switch over to your best party for the compulsory fights on each quests (generally, only 1 or 2). Unlike the original, there’s no dedicated area with boosted XP in Magnum, although thanks to the rangers, it’s possible to clear the game without too much need for grinding.
Subjective: Magnum is really what Quest should have been. If they’d incorporated most of the plot from Magnum into the original and stripped out some of the side-quests/unimportant new characters, they would have been able to produce a much stronger and more unified work, with only say two months additional development time - much less than it took to make Magnum. I’d strongly recommend playing at least VI and Sengoku before Quest, although there are references + recurring characters from all of the previous games, including 4.1 + 4.2.
Overall, I’d say that Quest + Magnum is definitely superior to 6, but behind Sengoku. Rance 9’s been confirmed to take place in Helman, so I hope they manage to both get the gameplay right, and strike a balance between introducing new characters, retaining long-running + important characters from the series and controlling the party size.