"Nether Bleed" Biome

Pretty much how it sounds. An underground biome much like the lush caves or deep dark, that appears pretty much to be a Nether Wastelands biome in the overworld. The idea being that the nether is "leaking" or "bleeding" into the overworld. As well as this there may also be new blocks that are similar to moss or sculk, that, when triggered will spread, replacing natural blocks around it. This could be an alternative source of a smaller amount of nether resources early game which provides and easier alternative for more casual players than traversing hundreds of blocks in the nether to find such resources. It makes the game slightly less linear as players would now have the option to avoid the nether if they are absolutely desperate to.