The Radiant Grudge

Additions:
+Stage 6:
-When this stage begins, the player receives a book called "Bone Knife", which states:
"When it flies towards you, do not panic. Use the Bone Knife to counter it. The knife gives you the Grace effect for 3 seconds, and as long as you have that, it cannot attack. If you see it morph into something you have never seen before, avoid it."
-The Grudge becomes more hostile, and its appearance changes
-It can fly towards the Player while passing through blocks. Before it appears it will make a noise. It can't attack if the Player has the Grace effect, which lasts for 3 seconds when it is applied with the Bone Knife. In this form if it catches you, it can not only raise the radiation bar, but also give the Player a new effect called Bleeding for 6 minutes.
This effect halves the health bar from 10 hearts to only 5. You won't be able to drink Milk Buckets while Bleeding is active...

-If the Player is above Y-level 55, then it can appear as a large skeletal creature. When it notices the Player it will start digging straight down, then disappears.
-Below Y-level 55 it will start digging towards the Player while breaking a large area of blocks.
-It is still able to break nearby torches, lanterns, and wooden doors.

+Radimaine Hideouts:
-In the Overworld tunnels mainly made of Radimaine blocks and Tuff can be located underground.
-Within these tunnels you can find Flowers of Remedy that are placed in glass containers.
-Flowers of Remedy can also be found in Barrels among many other useful items.
-A single Chest is always generated here, which can contain one of 3 types of written books.
-Be careful to not touch any radiant blocks!

+New Radimaine Blocks:
-Polished Radimaine can be crafted using 4 Radimaine, and it takes longer to break it than standard Radimaine
-Radimaine Bricks can be crafted using 4 Polished Radimaine
-Chiseled Radimaine Bricks can be crafted using 2 Radimaine Brick Slabs

+Added a new reddish overlay:
-It is displayed when the Grudge is way too close

Changes:
Stage 5 (3 minutes):
-Starting from this stage Mist Stalkers and Radiant Creepers can no longer spawn
-Grudge Chests will break when opened
-During this stage the Grudge won't attack, but it will make new types of ominous noises

Bone Knife:
-Has a new tooltip: "Allows you to counter Grudge for a short amount of time. (Right-click)"
-Changed texture
-Gives the Grace effect for 3 seconds for the cost of 1 durability
-Has a 15 second cooldown

Remedy Dust:
-Plays a sound effect when it is used to deplete the radiation bar by 1

Radiant Blocks:
-Touching them in Creative mode no longer raises the radiation bar by 1