dude how in the fuck do I win the labirynth floor 3?? this shit is so fucking annoying i cant even undestand why someone would put this shit in the game
Just keep exploring while avoiding the MG's as you see them. Best scenario is when you got both MG's following you one or two tiles away, thus giving you plenty of time to search the keys. There aren't dead ends in floor 3 that you can't see coming, unlike floor 4, so that shouldn't be a problem even for the dumbest player.
So the strategy in each floor (maybe excepting 4, but it worked for me anyway) is to go and hunt down the MG's (I mean find them, not engage in combat with them), and start looking for the keys once you've got the MG's all rounded up right behind (or one-two tiles away from) you.
Or, you can always grind a little. I was like level 60 when I passed the Labyrinth. And didn't have any problem fighting all of them, even in hard mode with 6 spirit (now I've got 10). So if you're, like, level 40 or less, you might have a slight difficulty passing dice rolls and fighting the hellhounds...