Okay, so I have killed Wall of Flesh on one of my bad worlds, and I want to summon it on my main world, but I'm worried all of my NPC's are going to die. I have a duplicate, but I would prefer not to use it. Any way to protect my NPC's?
You can fight the bosses away from your npc's or just move your npc's near a comfortable spot. Although it's not a total loss as npc's respawn the next day or so.
Get the best armor for the time/ Hellstone, and try to craft the nights edge or the fiery great sword at the least. I would also dig 3 wide hellevators Around you evil biome(s) to prevent it from spreading out of control since you already must control the new sprout from the WoF. Save up to at least 1 platinum and unlock steampunker right away so you can buy the clemtaminator to prevent the evil biome from spreading. Other than that, you want to smash every altar but one so you can get the third tier ore and mine it to get some decent Hardmode armor. Also another note after I unlock it is when you find Chlorophyte in the jungle leave one block of it and cover it in mud blocks since it will concert mud into more Chlorophyte since it becomes very important later. That’s pretty much the basic run down
Summoning the Boss again will NOT kill all your NPC'S It only will kill the guide. Also, a message will say that your guide has died.