You can defeat Withers normally, for which you will need strong armor and good weapons. Use bow and arrow for first stage, then you can use sword in second stage.
When the Wither has about half health, he goes to his second phase, where he dons wither armor, and here he becomes immune to arrows, so use your sword to kill him.
The Rise of King Wither
It’s been a long time since the death of the king of zombies: Xa-Tul, and the king of endermen: Feyd in the city of zombies where he saved Herder and others fellow villagers, Gameknight saw no major threat anywhere within the overworld, and, once again, he thought: maybe this is the end… Suddenly, an alarm was sounded, Gameknight is ran towards the walls, when he finally reached the wall, Hunter shouted something to Gameknight and aimed his enchanted bow towards a lower portal, Gameknight asked when he reached the top of the wall: “What’s wrong? ” “Don’t you see that portal?” Hunter looked at Gameknight, clearly annoyed. “Well… I can see it, but what’s wrong with the portal?” Just then, the wither skeletons step out of the portal, each clad in diamond-encrusted cuirasses and helmets, with iron boots and greaves. , some with bows, and some holding a diamond sword “I thought wither skeletons only had stone swords” there was a sound next to Gameknight, looking down, he saw the craftsman staring at wither skeletons, finally, a last wither skeleton to exit the portal, but, Gameknight can see this is different, he has fully enchanted diamond armor, he is holding an enchanted diamond sword, with a golden crown on his head, and one of his eyes is burning white , but with not hate, but a little kindness in his eyes, he stared at Gameknight, and Gameknight knew it, they couldn’t win against an army of 30 wither skeletons with better armor and swords and bows, but, the wither king raises only one hand and tell his army to hold fire, then he stepped forward and said mething and Gameknight and his friends are shocked
Chapter 2: unexpected enemy The Wither KIng said: “here, I am not going to fight you all, though I can defeat you easily, but there is a greater threat out there, we must cooperate to defeat it” “What is this, wither skeleton?” asked the hunter suspiciously, “I don’t trust monsters” “There is a new king of flames, I suspect he was reborn from charybdis, but it seems he was recreated from the power of Herobrine left in the lava lake, but I am different from him, i was not created by herobrine nor oracle, and not server herobrine, do you trust me now?” Gameknight asked: “if what you said is true, then… , we will go with you” hunter pushed gameknight,” do you really trust him? He’s a monster and might lead us into a trap” “I don’t want to risk the flames turning the overworld into nether again,” Gameknight replied” Digger nodded in agreement “If so, what are we waiting for?” Hunter winked at Gameknight, “Morgana still needs more fire powder for her potions” I’ll collect more wither skeletons while you villagers are preparing, also, tell your village witch to prepare a fire resistance potion and a potion of strength, and you also need a shield to protect yourself from those dangerous fireballs