Corruption [Custom Terrain] - Input Needed

Corruption Surface Test 
By Saixion 

Map Info. 
Im at the part of my terrian where im looking to build a netherlike land in the overworld and i kinda hit a brick wall. Im trying to find out what i should make the surface out of. I would appreciate any suggestions on what you think i should make the surface out of. 
*Note* all the mountains and surface objects are there to show its netherlike and wont be in the better version of this map.

Permissions: 
This map was made by me. Use it in anything you want just dont re-upload anywhere and dont link it behind any monetized links (ad.fly, ad.focus, linkcash, etc.) 

Tools Used: 
World Painter 
MCEdit 
WorldEdit 
NBTExplorer 
Chunky 
Minutor