[YoshL]

you're going to have to take on the friday dungeon expert difficulty if you want those
http://puzzledragonx.com/en/mission.asp?m=65

almost the same deal as the masks, everything has 100000 defense. either you bring as many monsters in with double typing so you can do a max of 12 damage to 1 thing per turn (makes the dungeon not that bad with things being on a 3 turn timer, and everything has <= 10 hp other than the dub myth) or you get a big enough multiplier and burst their faces