Witherrack Block

I love the Caves & Cliffs update and I was inspired by the Grimstone generating in the deep underground!

I imagined a new Block: the Witherrack

The Witherrack is a darker, withered Netherrack variant and it can be found in the Deep Nether below Y=0

Other than adding a darker version of Nether Bricks, the purpose of this block is to give the player additional difficulties below Y=0: if the player stands still for 1 second, it gets Wither Damage, when they start moving the Wither Effect lasts for 5 seconds and then stops. But if you place a Wither Rose on it (instantly becomes a Golden Rose), the area around 20x20x20 becomes harmless.