Hello again and welcome to another one command creation! This is not what it sounds like. In this command there are new enemies, dungeons containing loot, and a corrupted world. Lets jump straight into it!

World Corruption:
This adds an interesting twist to the otherwise normal survival. What it does is randomly delete blocks around all entities. Please note that because of that, the game will lag more. This can also place new blocks that infect the world around it. The infected block has to have the head of the infection lit on fire in order to stop the spreading. If you don't want to lose any special builds that aren't backed up, I would recommend backing the world up before using this creation.

New Enemies:

Corrupted Soldier
-Can drop player head, leather chestplate, leather leggings, leather boots, iron sword, and a smoke bomb that blinds any entities that go through it as well as normal zombie drops.
-Has leather armor and a player head as armor.
-Spawns on sand blocks.

Corrupted Archer
-Can drop normal skeleton items and a Corrupted Bow containing the enchantments Power I, Punch I and Flame.
-They don't have any armor.
-Spawns on grass blocks.

Corrupted Killer Rabbit
-Can drop normal rabbit drops, bones, carrots, potatoes and wheat seeds.
-Spawns on grass blocks.

Corrupted Horse
-Can drop all Corrupted Archer drops and normal zombie horse drops.
-Spawns on grass blocks.

Suicide Spider
-Can drop TNT and normal cave spider drops.
-Spawns on grass blocks.

Castle Guardian
-Can drop leather chestplates, leather leggings, and leather boots and can drop a stone sword.
-Spawns inside castles.

Forbidden Castle Archer
-Can drop skeleton drops and chain chestplates, chain leggings, and chain boots.
-Spawns inside castles.

Potion Guardian(Witch)
-Can drop normal witch drops, a magma cream and chain helmets, boots and leggings.
-Spawns inside castles.

Wither Guardian
-Can drop normal wither skeleton items, iron armor and an iron sword with Sharpness I.
-Spawns inside castles.

Forbidden Castle King(Boss)
-Can drop normal wither skeleton items, and its crown with Protection IV, Fire Protection III, Blast Protection II, Projectile Protection III, and Thorns I.
-The King has diamond armor(excluding helmet).
-Spawns inside castles.

-The infected block is an enemy that flies around spreading netherrack. It cannot be killed unless you light the head of it on fire.

New Dungeons:

The Forbidden Castle
-Has 5 levels, each one increasingly more difficult.
-Each level has its own unique mob.
-4 of the 5 levels has randomly generated loot.

Features:
-Adds 10 new mobs that can spawn and some have custom drops
-Adds a new dungeon
-Adds 1 boss(included in the 10 new mobs)
-Multiplayer compatible
-Efficiently handles all entities when natural events occur
-Has 2 naturally occurring events(Block destroyer and infected blocks)

Notes:
-Please be sure to back up any saves you are worried might be ruined before using this command.
-Lag is frequent in this large command creation, so if your computer has difficulties handling it, sorry.
-This command requires 1.9 or greater.

Command:
This command requires 1.9 or greater.
1.9 to 1.10: http://pastebin.com/Q7CntvFY
1.11 or greater: http://pastebin.com/F2YkXYng

Credits:
Made by me
Used Command Combiner 1.9
Used JSON Creator for Minecraft
Used MCStacker