First off, Duelle, before I forget: *hands Kusuha's special energy drink* for guessing Ibis correctly.

Also, on topic: I see what you did there. Hard mode being 'unlocked' through execution of the dungeon/content is actually a pretty good idea. Like a dungeon wherein if you take special paths you trigger the hard mode (i'm not exactly against a small extension of the map during hard mode, as long as it's not like, more than 20% of the size of the current map). Or a boss that if you DPS really hard or completely incapacitate it's parts enters into hyper mode.

That is, in fact, an ever better idea than mine.