I'm not sure how many of your have been down to the Labyrinth to challenge the crazed Minotaur Meraktus but if you have the patience and like a challenge it can be alot of fun and I strongly suggest it. It's definately not for everyone and there are tricks that can make it easier but I'll let you figure them out for yourselves.
Thus far from my experience solo'ing it, it takes a little over an hour to spawn the Champion, sometimes longer... like I said patience is a must in the Labyrinth.
I'm not sure how much faster a large guild could prop him up because it's really dependent on the minotaurs spawning. The strategy of running all over the entire Labyrinth fighting Pyre and Reptalons and perhaps even rend in order to spawn Merkatus well...it's a deathwish. It can get really crazy down there in a split second if you play yours cards wrong. Patience and determination is really what is needed. So anyone who enjoy's soloing Paroxysmus or Dreadhorn should make a trip down and test your metal against the strongest the Labyrinth has to offer. With the introduction of Replica's the trip might actually be worthwhile.
Direction are head all the way to the back of the Labryinth. Outside the Gate is where the majority of Minotaurs will spawn. Inside the gate is the large building where Meraktus will appear with his Tormented Minotaurs.
It takes ALOT of killing of minotaurs and the progression will start with the shouting "I see invaders! Must warn the others!". Which will be followed by "Aid the others! Kill the invaders!" and finally after approximately an hour of slaying Minotaurs A Minotaur Captian bellows, "Meraktus has arrived!". You will only hear the "Meraktus has arrived!" message once so pay close attention. It's a good idea to keep an eye on the large building with a stealther to see if you missed the message and he did indeed arrive.
Meraktus and his crew of Minotaurs are not to be trifle with. It might be a good idea to take on Dreadhorn or Paroxysmus before taking on Meraktus even though his HP is alot lower and he goes down fast he hits like a ton of bricks. I can't remember the last time I took so many dirtnaps but for me it has been alot of fun and a great way for solo players to get replicas.
Good luck and be sure to share your experiences.

The final Battle with the Minotaurs before their Master Appears:

A Close up or Meraktus and his minions (I just need to learn how to edit screenshots better..sorry TM!LOL!):

Cornered by Merkatus the Tormented:
