New Mob Spawner Dungeon when near Grimstone

Right now, they look very out of place when near Grimstone. However, it would not only be better if the Cobblestone was replaced with Grimstone, but also have a total upgrade as well. My suggestions for this new mob spawner dungeon are listed below.

*I am not trying to say that all of these have to be with the dungeon. These are only suggestions that can be picked out or left out.

For the Mob Spawner Block:

• Mobs spawn in larger quantities
• Mobs spawn more frequently
• Mobs most likely spawn with potion effects
• Completely new mob that can only be spawned by this spawner
• Spawner is slightly harder to break

For the room:

• Better loot is generated
• Room area is bigger