I disagree with the mirror wizzrobe not being a boss. Now granted, in the original Zelda 1 quest where there is no such thing as 'mirrors' or a mirror shield, Zelda Classic added all those. But in a custom quest, the mirror wizzrobe can be an excellent boss for a mid-tier dungeon. Or at the very least a optional dungeon. Most Zelda bosses now have some sort of gimmick these days anyway, so the mirror wizzrobe seems to be no different.
You see, its fine to have a gimmick, or require some odd strategy, the the Mirror Wizrobe is more like a time-waster. You usually waste more time waiting for them to align, and the game AI to home on you, in order to harm them, by having them kill themselves. The idea for this enemy, originates in Zelda II, where you need to use the reflect spell to kill one of the bosses, but while it was original in that game, it is just stale now.
The ZII boss was also far more demanding, the first time you reached him, and if you didn't haver the clue on how to beat him, or the reflect spell, you were toast.
A real Mirror Wizrobe, as a boss idea, would work better if you changed it up a good deal:
First, I would think that stages in a fight would be best; using tribbling tricks, or a scripted enemy of some kind. Require the player to strike the enemy X-times with magic, or something equally appropriate, then have the enemy go nuts, homing around, and shooting fireballs or spells, that you need to reflect at it. Al off this without warp tiles, of course, to avoid breaking up the flow. Something like the Ganon fights, but with a slightly different twist.
Second, I would ensure that there are two types of spells: One that can be reflected, and one that cannot, so that the player must pay attention, dodging the unblockable shots, like the Agahnim battle in TotG/LttP.
The real magic here, in 2.5, is that you could do this without warp tiles; and in fact, you could probably do it without scripts; or at least, with very minimalistic scripts.
Boss fights that have no strategy, and are just monster rushes, or waiting games, are just silly; and that's how I classify a Mirror Wizrobe. You just need to wait, sometimes for quite a while, for the AI to lock onto you, and reflect shots. Pretty mindless, in the end. Various other things cna be added, such as damage combos, to make it a bit harder, but most of the time, adding obstacles can make it take even longer for the little bugger to decided to cast a spell. How manh times have you seen these guys just float past, and ignore the player, rather than locking on and going nuts.
The red version, vulnerable only to reflected magic, is actually a much better enemy. There are also some cases where taking damage is mandatory in these fights, which is generally bad design.
It still doesn't fit, with changes to 1st.qst/2nd.st for level balancing, which is all I was getting at, but I think that some of the 'weird' enemies in ZC are horribly overused. Some of them are plain stupid, like the 'Magic Octorock'. That's an enemy type that really only makes sense for very late-game ideas, in difficult quests, yet I see them placed in L1 dungeons, like some kind of sick joke.
You may as well start the player with one heart, and standing on a damage combo as the arrival square.
Here, mate, see if you can play this....
Start. Dead.
I could make a quest that is nothing but an exposition of bad ideas: how about this:
A full DMAP spike maze, with instant-death combos along the path, especially on the edge of 'next' screens, so while wandering through the spikes, trying to avoid touching them, just waking on the next screen causes a death. Then, force the player to go all the way own one path in the maze to get a key, then all the way back to take the other path; all with one heart. Die, and you need to start from the beginning, and you would lose that key too. Yes, you need to do the entire thing, without ever making any error, and you need to know where all of the off-screen traps are.
It would probably take days to complete the 'game', just out of frustration; and I already know that someone will make this, now that I described it, just because they think it's hilarious.
Once you finish the maze, you win, with a nice ending sequence of a black screen, with white text:
'Congraturations. You are nerdy enough to play this Kusoge! Game of End!!!'