Note: This is not in a game, nor is it in any mod.
Feel free to critisize any part of this and point out any mistakes I might have made! Comments are always appreciated :D
This may or may not have more content being added, depending on the comments I receive.
Floating Island Chests
All chests in floating islands now contain the Small Cloud, two of which, when crafted together with a Soul of Night, makes the Thunderclap. Using this item in the forest biome will cause a bright flash, and a lightning-strike effect in the background. This means that a Cloud has spawned somewhere in the world.
The Cloud Biome
The Cloud Biome spawns in an altitude of at least 100 blocks above the highest block in the area (not world) in a random area in the sky that is 200 blocks away from the spawn and above a hallowed area. This Cloud destroys all other blocks upon generation except for filled chests, and is made out of the new Cloud Puff material.
Using Unholy Water on the Cloud Puffs will cause them to turn into the Thunder Cloud material, while using Holy Water turns it back. Each is it's respective biome and they don't spread without help from a player. The Thunder Cloud biome does not host any corruption enemies while the Cloud Biome does not host any Hallowed enemies.
The Thunder Cloud, when placed, will cause any player nearby to get hit 10 damage at a relatively high speed (reduced by defence) and deals a huge amount of knockback, but wearing any knockback-negating items causes it to lessen it's effect, dealing a very little bit of knockback only (but still doing some knockback).
The Cloud Puff, when placed, will turn into an inactive version when stood on too long (five seconds), causing the player to fall through. The inactive version of the Cloud Puff cannot be mined, and will turn back to the original version in two seconds.
An immortal which floats slowly from one side of the screen to the other, dealing 100 damage upon impact.
Has a low chance of spawning (like that of Pinky) and deals 40 damage upon impact. Has a 80% chance for magic attacks to miss it completely, and a 40% chance for ranged attacks to miss it. Drops the Four-leaf Clover (50% chance) and 50-99 gold upon death.
Rarely falls from the sky much like stars, and deal 500 damage upon impact. It has one health and killing before it lands it will cause it to drop the Lightning Shard.
Spazmatism's little brother. It is similar in sprite and attack patterns but the size of a Wandering Eye. It deals half as much damage and 200 health.
Has the sprite of the Chaos Elemental, and the same stats except that it cannot teleport, instead moving very rapidly.
Dealing 20 damage rapidly. Jumps twice as high as a normal slime, floating down and attempting to land on you. It drops Cloud Puffs instead of Gel.
Opposite of the Fire Imp. It shoots Water-bolts which inflict "Slowed".
Has a low chance of spawning (like that of Pinky) and deals 30 damage upon impact. Has a 30% chance for any attack to miss it completely. Drops the Rainbow Candy (50% chance) and 50-99 gold upon death.\
Has the Unicorn AI. It looks like a dog made out of cloud and deals 20 damage. It fades away when you run into it (despawning and hence dropping no items). It has 120 health and is not affected by knockback. Drops Cloud Puffs and the White Fang (30% chance).
Crafted from one Breaker Blade, one Saphire, one Diamond, fifty Cloud and ten Soul of Fright. Deals 40 damage at a fast speed and shoots small slow-moving Vortexes which travel as far as the Crystal Storm's attack and deal 10 damage at a insanely fast speed with negative knockback to keep the enemy within the vortex.
Lightning Charged Repeater [Credits to Mace2theFace]
Crafted from one Mythril Repeater, 4 topaz, 2 Lightning Shards, 50 Thunder Clouds and one Charged Essence. This repeater turns normal arrows into Lightning Arrows, much like the molten fury. It deals 40 ranged damage.
The Lightning Arrows move extremely fast and their damage is based on how long you hold down the left mouse button for. The arrows upon impact cause a chain reaction of magic damages to nearby enemies, halving the total damage each time the damage jumps to another enemy and stop when the damage reaches 1. The damage can "jump" back to the enemy first hit. The lowest damage possible with the arrows is 1 damage (with the addition of the Repeater's damage) while the highest damage possible with the arrows is 70 (but you need to charge the arrow for at least 10 seconds).
Accessory, 10% chance to negate damage.
Crafted from two Lightning Shards (see Lightning Bolt), 1 White Fang (see Cloudster) and ten iron bars. Summons Zeus (Boss)
Gives the "Hyper" buff for five minutes. The buff doubles your speed and jump-height, but halves your defence. It also allows you to use the Rainbow Rod without any mana-consumption. Tooltip: Believe the rainbow!
Crafted into Lightning Rod and the Demon Blade. Tooltip: Its white and clean!
Crafted from the White Fang, 4 Wood and 5 Soul of Fright. It uses 40 mana with each use and heals any NPC in front of you to full health, hostile or not.
Lightning Cloak [Credit to ComradeCat]
Crafted from one Star Cloak, one Lightning Shard and one Charged Essence (See Zeus). Has the same effect of the Star Cloak, except that one mini Lightning Bolt falls instead, slightly curving towards the closest enemy. This Lightning Bolt deals 70 damage.
Thunder Armour Set
Worn in the helmet slot, it gives 1 defence. It also gives the "Hunter" buff lasting half a second every two seconds. This is to give a "sonar" effect. Crafted from one Thunder Shard, Goggles, five iron bars, five Soul of Sight and twenty wires.
Thunder Exoskeleton Top
Worn in the shirt slot, it gives 20 defence. Crafted from two Thunder Shards, one Iron Chainmail and twenty wires.
Thunder Exoskeleteon Bottom
Worn in the pants slot, it gives 10 defence. Crafted from two Thunder Shards, one Iron Greaves and twenty wires.
When worn together, the set bonus allows the player to move 40% faster and any enemy touched will gain the "Electrocuted" debuff, which causes enemies to take 10 damage with knockback every second.
The boss summoned by the Lightning Rod, Zeus spawns above the height limit, meaning you can't see him. You can damage him by firing ranged weapons above the skyline, or by deflecting the lightning bolts that rain on you with a sword.
He has a total of 100,000 health, and can be fought anytime. The lightning bolts deal 80 damage each and spawn quickly when Zeus is present. These types of bolts are smaller than the normal Lightning Bolts and are therefore easily dodgeable when there is only one heading your way.
As Zeus cannot be seen directly, you can't tell how much health he has. However, you can estimate how low his health is by the spawnrate of the lightning bolts. The bolts spawn at around 1 per second when Zeus is at full health, slowly increasing to 8 per second right before he dies (1 health). He drops Charged Essence upon death.