Amazing Triangle

So I have been planning my next session for my home campaign and I thought I would let some of my planning ideas come out here on Loremaster for others to use.
I have been reading a few blogs, mostly Angry DM and Slyflourish , for inspiration for my next game. I have had a lack of a big dungeon in my game so far. On the Angry DM blog he has written the "Slaughterhouse Project." Not only is it a great name for a Dungeons and Dragons thing it is a great planning idea. In a nut shell for those that haven't read it, you create zones where a brand of monster are and set an XP budget when the monsters reach a certain level the zone changes. If they zone never takes enough of a hit then it regenerates. This is an oversimplification of his process mind you but it was how I could easily use it. Now lets take a look at my zones, just in case my players check this I will leave out one zone. It will be enough to keep them on their toes.
So as background I looked up real holes in the ground and their sizes.
This was the inspiration for the Dungeon's location and
Now my Zones:
Since all of the pictures I found were of mines I thought it would be cool to have the hole be some kind of mining operation. So I named this the Slave mining operations. I figured that the slaves have been this way so long that they don't have any hope left so they might just fight the PCs if the try to free them.
The next two zones were inspired by environmental ideas. One was a Magma chamber, full of fire elemental types. I had planned to mix in earth and air elementals changed to have the fire elemental characteristics. This was until I saw just how many fire elemental monsters there were. The second environmental zone was the darkness zone. A place that the shadowfell touches in many places. Where all light sources are cut to a fraction of their normal strength.
The next zone was this idea that a set of monsters would keep worshiping something powerful that came to the area and would keep changing what they worshiped if someone came and tested their resolve (killed their master). This was a funny zone as it has a ton of altars that keep getting changed who they worship. Each time the Altars change hands they have a different aura depending on what is being worshiped.
The final zone is the Cathedral that the players have been searching for in the last two sessions. This I went to Eberron for inspiration and went with the Hag Sisters, if you don't know them they own a whole kingdom and have gnolls as their main citizen. So to pay homage to this I am using yuan-ti with the gnoll pack trait. Then I needed my bad guys, I know the other guys as the good guys is hard to take. My party has had some trouble with the far realms so I decided to make them all aberrant creatures that have some kind of exaggerated feature. Tentacle arms, quills, and Eye. My favorite was the half orc rage beast, I had this idea of a creature that had been beaten and tested by wizards for so long that they have made him a tough target for wizards to kill.
So if you want to know more I can give out more details as we go through it or I can send you a PDF of my whole set up.