Fee Fi Fo Fum 2 cleared!
First of all, there is a slight visual bug in this dungeon. This screenshot is taken after beating the final boss, and as you can see the walls don't really look right - these are the walls bordering the ones I destroyed with knockback.
http://prntscr.com/l3s6auNow for the run.
This dungeon is difficult! I would probably rate it as the Naga City of the pack so far. Nasty enemy pool and nasty boss who has multiple forms and forces you to fight tough enemies during the boss fight (though the Half-Dragon actually makes pretty short work of them if you position them properly). And then the final boss is kind of a pushover unless you've completely spent all of your resources.
I had a really good time working my way through this - I had a harder time than Lekon's Table or Flooded Foundry, though that might be in part because my strategy was far from ideal here. Again - the lore here is also pretty great, and I'm already itching to go for Endless Blizzard right away - I think I'll try and clear Fee Fi Fo Fum 3 first, though, because I want to see what the new class is all about.
The reward for this dungeon looks... insanely strong, to be honest. The drawback is huge, of course, but can be circumvented with a well-timed Transmutation Seal in case you want TT or Dracul for that extra push in the endgame. And aside from that, it turns anyone into a strong regen fighter and makes regen fighters monstrously strong. In particular, I can see this item making a Gorgon immensely strong - if you prep Patches, buy a Tower Shield/Elven Boots? Insane. I might just throw this into a run just for fun.