The Radiant Grudge

 First Stage (9 minutes)

• The Grudge will lurk near you, but first it will release a greenish mist from the ground. When you go near the mist the Grudge will appear.
• The Grudge Head appears if the player attempts to pillar up while the Grudge is near.

Second Stage (13 minutes)

• When this stage begins, the player receives a book called "Remedy", which states:
  "You cannot let the radiation bar fill up. Find Flowers of Remedy to deplete 1 dot from the bar."
• When switching stages, you can hear some ominous noises from the distance.
• The Grudge will continue to lurk near you, but nearby torches, lanterns, and wooden doors can get destroyed by it.
• Radiant Creepers start to appear that look like regular ones, but instead of exploding, they summon the Grudge.
• Sometimes it can drop Rotting Flesh blocks on you, which slow you down and drain your hunger. These will make noise so it will be more difficult to hear if a stalker mist is near. These blocks draw zombies towards themselves. When a zombie gets too close, the block will break, as if the zombie ate the block.
• Bonus chests can start appearing in the world, but beware! There is a 50/50 chance that it is a legit chest, or the Grudge can hide inside it.

Third Stage (11 minutes)

• When this stage begins, the player receives a book called "Be Ready", which states:
  "It is growing increasingly unstable. Keep Remedy Dust on hand. When it reveals its eye and attacks with a weapon, be ready for it."
• Besides the mist ability, all previous ones from stage 2 will still be present.
• The previous mist event has been replaced with a mist stalker one. At night, a mist stalker can spawn on the surface, and it will start to slowly approach the player while breaking blocks in its path. The player needs to listen to the sound of the mist because it won't be visible, and if the mist gets too close then it speeds and begins to emit particles. Once it collides with the player the Grudge will spawn, but only if it's not already near. If it does exist then the mist will give the player Weakness effect and then it despawns.
• Poisonous spikes can come out of the ground under the player, which will then disappear.
• The Grudge becomes more unpredictable.
• Weird sounds will be a bit more frequent.
• The Grudge can appear as a floating head, which will quickly charge at the player, raising the radiation bar by 1.
• It can also spawn with glowing green particles that fly towards the sky. In this state, the Grudge will slowly walk towards the player while destroying blocks, speeding up if the player gets too close. During this encounter, it will turn Grass Blocks into Coarse Dirt and plants into Dead Bushes. Sometimes poisonous spikes can appear at the same time as this event.

Fourth Stage (lasts as long as the Grudge is not damaged)

• Begins at the end of Stage 3 if you fail to damage the Grudge using Remedy Dust when it reveals its eye.
• Lasts as long as the Grudge is not damaged with a Remedy Dust.
• Besides the bonus chests, floating head, and rotting flesh block ability, all previous ones from stage 3 will still be present.
• The Grudge can ambush the player while holding a knife, and in this state its eye will be visible. The Grudge can ambush the player while holding a knife, and in this state its eye will be visible.
  It won't raise the radiation bar on contact; instead, it starts damaging the player and will disappear once the player is below 6 HP. Once you have Remedy Dust, use it on the Grudge to begin Stage 5 (W.I.P).
• The floating head event has been replaced with a projection one. The Grudge ambushes the player and there is a 50/50 chance that when it reaches the player, it will either simply disappear or appear as a floating head nearby.
• X0R1 can appear in the distance, floating towards the player and passing through blocks. X0R1 speeds up once the player is within 20 blocks and when getting too close it gives the player a written book then disappears. Once the book is spawned X0R1 no longer appears during Stage 4.

Fifth Stage W.I.P

• Begins when the Grudge is damaged using a Remedy Dust during Stage 4. The Bone Knife is dropped by the Grudge when it is damaged. It deals 7 melee damage and has higher attack speed than a diamond sword (1.8 instead of 1.6). It will be important.
• It works just like Stage 3, however events are more uncommon.
  
  

More Stages are planned!