Yeah, playing NC I make it to the last 3/last boss every time, I just sometimes run out of steam there. There's only four "real" bosses to me; the wraith, goo, bandit, and final bosses. The first two demand a lot of mana, the third sets up Curse, and so far resists have been my strategy on getting through NC. The last guy is just plain annoying.
I dunno, the original Matron of Flame sounds a tad ridonk, but it'd be nice to have something special for dragons. Hmmm. Maybe a Miser kind of level? Set Matron's damage to something ridiculous like 150+, but let the amount of gold you're carrying act like a shield? Make you act like a dragon to win. Ties in nicely with the "not taking a trophy at the end" message.
EDIT: So close, yet so far.
Side note: Something to maybe patch in post-release; Hall of Records. For stuff like this, except for all the stats the game keeps track of.