I think its crazy how you never picked up the armor. It's definitely in the upper (or lower since we're going down...?) middle dungeon levels but I may have picked it up from some room though. No monster drop, well, at least from what I remember 8 years ago.
I totally understand what you are saying, it seems the game may only program certain items to drop and certain ones to never drop, even though they are coded into the game.
What cause the sword and helmet to drop and not all three? I suspect it is the randomized nature of the game. For example, it is possible that only the armor and sword to drop in one game, but the next time you start over again on a new game all three may drop, or only one of the items... Maybe none of his gear.
I think you are the first person this entire topic that has claimed to get all 3 pieces in a single playthrough, which was exactly the answer I needed, along with the floor (which someone else answered before though)
However, I'm still not 100% convinced it'll drop around those floors just yet, considering I had to fight a different color swapped monkey/guy with club which maaaaaybeeee shows up on the higher dungeon levels. So for now, I'm running around in 18 with Koji (who is only a measly level 11 and needs to rescue Clair) and will stay there for a long time until I am DAMN COMPLETELY 10000% SURE something drops or doesn't.
But of course X-2 HD came out so that's just...sucking my time. XD *tosses X underneath bed* Sorry Ehrgeiz. If only you sang pop songs and danced for me.
UPDATE: Played a little bit today. A little bit dramatic. And a little bit drunk.
FINALLY saved Clair on dungeon level 20 but, newbie Koji (level 16 now woot woot!) died in the process though. Saved Koji, picked up most of the equips Clair could carry and used the newly acquired dragon wing to teleport outta there! After healing, repairing equips and selling fodder to make inventory space, Clair jumped back through the portal ready to kick, slash and curb stomp the rest of the way to reveal most of the map of dungeon level 20. And then "IT" happened...
Ran into the normal, run-of-the-mill upside down L shaped hallway in dungeon level 20 and there it was. I thought to myself, 'Is this a dream? Could it really be?' And my mind's eye replied, "Open your eyes and you shall see, what is in front of you, is meant to be."
Lying on the ground all innocently and all its glory was Sasuke's Armor. Boo-yah. But Clair had to fight her way to it since there were those eye monster thingies running around in the halls trying to run off with my prize.
WANTED: Sasuke's Sword REWARD: Hugs and kisses?
Edited: Speaking of Ken Mishima, I JUST picked up the God Hand gloves XD