[1.15.2 Custom Terrain Generation]

I've been working on creating a mod for minecraft based on the Stormlight Archive. I've already gotten some of the items made and am interested in creating a custom biome. This would be the shattered plains, which would look something like the picture below. I am unsure on how to approach creating a biome that will create chasms like that. Any help would be appreciated.  

 

[Forge 1.8.0 Wont Launch and Crashes.]

I don't remember where I got this Optifine from. I removed it and my game launched. Thanks for suggesting this I never thought that it would be the cause as it had never caused any issues before hand.

[Forge 1.8.0 Wont Launch and Crashes.]

Sometime yesterday my Minecraft forge stopped functioning completely. I'm running Forge 1.8.0 right now with a few different mods listed below:

 

[1.8]bspkrsCore-universal-7.01

BetterSprinting  MC-1.8  v1.1.1

LunatriusCore-1.8-1.1.2.30-universal

OptiFine 1.8

Schematica-1.8-1.7.7.140-universal

 

I had been using Forge recently before this happened and it was functioning fine. Now it isn't and I have no idea why. I've tried re-installing Forge, Minecraft, and Java. Nothing worked. I'll post my crash log in a Pastebin. Can someone help me fix this? 

 

https://pastebin.com/b9pMgZTY