this guide should be able to help you from stopping the evil biomes from spreading any further
 
 

Hell elevators everywhere

so basically make a 5 or 6 block wide hell elevator on both sides of the evil biome to basically quarantine the biome and boom you’re done its as shrimple as that
 
 

 
 
 

Blocks not affected by evils (less effective)

separate the biome by putting a 5 blocks between the evil and any biome
 
i recommend bricks of any kind, wood, and clay
 

 
 

 
 
Here we come to an end for the How to prevent evil from spreading – Terraria guide. I hope this guide has helped you with your gameplay. If you have something to add to this guide or believe we forgot some information to add, please let us know via comment! We check each comment manually by approving them!