Hostile Mobs
Hello, in the nether there are different hostile mobs than in the overworld. One such mob is a ghast which shoots fireballs that can be deflected by a sword (preferably a Dimond one)
These are ghast that are also immune to death by lava so when you try and make it burn alive use one of its own deflected fireballs or by arrows.
I know this is not a realistic version but all you need to do is avoid being hit and not get the wither effect while hitting it. A useful tip is to place blocks at head level so they do not see you and you can repeatedly hit them until they die.
This is the Zombie Piglin. It is a mutated pig that resides in the Nether and is open to trade with gold ingots for various items like ender pearls that you can otherwise get from killing ender men. You can only safely move among them and trade with them by wearing a piece of gold armor and trapping them in holes to barter.