The ending of Phantasie came at me all of a sudden. I had intended to get in at least one more posting before I won. This is par-for-the-course in some of these older games, though, which don't telegraph their final chapters the way that modern games do.
Many of the assumptions that I made about the game in the last posting turned out to be false. First, there are no side quests--what I thought were side quests were just steps along the path to the main quest (although there is at least one dungeon that seems to serve no purpose but to provide an interesting diversion). Second, there aren't a fixed number of Black Knights. Although the game repeatedly tells you there are nine, they must regenerate, because I must have killed 30-40 of them.
In your progress through the Phantasie dungeons, you meet the heroes of the pre-Nikademus era: the dwarven fighter Kilmor, the sage Filmon, and Lord Wood. Each gives you clues, items, and passwords to help you along the path through the dungeons and, consequently, the main quest. Your progress culminates with a visit to the city of the gods, where you meet Zeus himself, and then finally to the castle of Nikademus. [Later edit: 5 years after I posted this, an anonymous reader pointed out that you don't actually fight Nikademus in this game; you fight the Black Lord, leader of the Black Knights. Every time I say "Nikademus" from here on, I mean the Black Lord. I was under this misapprehension for a long time!]
The reason I was surprised by the ending was that the game led me to believe I had to collect nine rings along the way. But when the game finished, I only had six of them. Phantasie makes the origin of the "nine rings" concept quite clear and pays homage via the name of one of the game's villains.
The odd-dungeon-out is the interesting dungeon of the Bleebs, where you encounter a multi-colored race that offers you a series of riddles having to do with which color tells the truth and which lies. I like it when games throw logic puzzles at you like this. The Bard's Tale, in retrospect, offered some fun riddles that I forgot to mention in my postings.
Some of the encounters give you at least some ability to role-play, although we're nowhere near modern games in dialog and freedom of decisions. You can choose whether to rob a jewelry store, whether to pray to or deface statues, and whether to rescue a young maiden or an old man from lava. (To be fair, though, if you rescue the young maiden you can't continue in the main quest.)
Nikademus himself is pretty tough, repeatedly casting spells that do dozens of points of damage to all of your characters. Fighters barely damage him. The only way to defeat him--like the only way to defeat a lot of other big bosses in the game--is to repeatedly cast Fireflash IV.
The game lets you keep winning after the final battle--in fact, even after the final battle, Black Knights continue to roam the land and you can go back and defeat Nikademus again. In fact, you have to go back if you want to finish the dungeon and get the final scroll.
I made a video of the end game--no sound this time. Final accounting to follow in another post.