Wither Skeleton Knight

The nether fortresses are quite easy to raid as of current, blazes are fairly easy to take out and wither Skeletons can be easily avoided. But what if there was a rare, more powerful and also more smart wither skeleton variant? The Wither Skeleton Knight could be like the piglin brute, whenever a wither skeleton spawns in a nether fortress it has a very small chance of spawning as a knight instead. This knight would be slow but very tanky, it would have a lot of health and wield a giant iron sword that it slams it's enemies with. If you attempted to hide behind a 3 block gap, the wither skeleton knight would crouch down and would become two blocks in size, meaning it will just go straight past that! If you defeated this knight it would have a rare chance to drop it's huge sword. While holding this you will have reduced speed, but a bonus of this sword is that it inflicts the wither effect on anything you hit it with