Lore

The Decimation Mod adds new Lore to Terraria aswell as some unique lore for the mods backstory and bosses.

Story
Many thousands of years ago in Terraria, Ra ruled the land, the people he created gave sacrifices to him, prayed to him for good fortune, and centered their lifestyle around him.

One day however, one man dared to defy Ra. He began the Euclidian Cult and devoted himself to Cthulhu, Lord of R'yleh. Ra soon discovered that the goal of this mysterious man was to unleash Cthulhu's wrath upon his peaceful world, Wreaking havoc upon his beloved people. Ra selected the best of his men to acquire the Euclidium tablet from the cult, the centerpiece of the cults worship. Upon it being taken from the cult, Cthulhu's rage grew, he breached the dimensional barrier and attacked the land, its people, and the innocent creatures. He corrupted areas that were once lush forest, he painted some of the world red with the blood of its denizens Crushing the peaceful giants into extinction. His corruptive power even effected the underworld, creating the dreaded Kight. Ra assembled his best men and his strongest creations to defeat Cthulhu. The battle went on for decades but Ra had triumphed. Cthulhu's corpse was thrown back through the dimensional barrier to R'yleh. The dimensional barrier sealed, Ra Created Monstrous beasts to protect both the barrier and his people, he created a monstrous worm to protect the orbs of coalesced, unreleased darkness within the corruption. He trapped the Kight within the earths core and Created Arachnis to keep it trapped within. He trapped the souls of the corruption and hallow within the underworld, as for the man who was responsible, he was cursed to forever guard the souls against his own will, he was given a disgusting monstrous form and was from then on known only as "The Wall of Flesh". However Ra's precious world had been given unrepairable damage. The bird men ravaged by a horrible machine conceived within the kight, some blood encrusted forests and caves forever marked with Cthulhu's wrath. Others forever cursed with the vile Corruption.

The Lunar Cult
The few members of the Euclidian Cult able to evade Ra's Wrath formed the lunar cult to pray to the mighty moon lord, their leader driven insane after seeing Cthulhu for himself, allowed none of them to pledge loyalty to Ra, he killed anyone who dared to defy the moon lords will. They crafted a lunar tablet out of Meteorite and what small reserves of Euclidium they had left. Exiled to the dungeon, they created Skeletron with remains of a giant slain in the Crimson, and cursed an adventurer to guard the dungeons entrance for all eternity. Thousands of years passed and one by one each cultist lost their mind. Eager to appease their god they became machine-like in prayer to the lunar tablet

The Dwarven Kingdom and Kightmares Origins
Centuries ago, before the underworld was a fiery prison for the damned, two races dominated the deepest parts of the Earth: the furtive, witty goblins, and the once-grand dwarves. The two races were strong allies, and devoted followers of Ra, constructing great machines in the likes of the deity's creations. They relied on each other for machines and traded materials, and were heavily recognized by the humans that walked the surface. Overtime, however, their relations began to break down. The goblins, having discovered the arts of magic, saw less need for the hardware of the dwarven race. Having less of an income of ore from the goblin miners, the dwarven race lost the splendor that it once had. One night, however, this relationship finally snapped. Having been denied the hand of the dwarven king's daughter in marriage, the prince of the goblins was furious. Assassins breached the dwarven kingdom, and the king's throat was slashed. A war erupted, and the clash between the two forces was enough to make the underground tremble. Months later, the dwarves emerged victorious. Any remaining goblins were banished to the surface, where they left the island, building strongholds in far-away lands. There, they slaughtered anyone not of goblin origin, and shunned those of their race who created contraptions as the dwarves did. Though the dwarves rejoiced in their victory, they were unaware. Having exiled the goblin scouts, they received no news of the impending danger.

The next few days marked the beginning of Cthulhu's invasion. The great machines of the dwarves could barely keep the creature at bay, before Cthulhu twisted and corrupted them with vile sorceries, making them turn against their creators. Armed with only weak explosives, the dwarves were annihilated, only a few having retreated to the surface, where they wander aimlessly, looking for foragers to sell their wares to. The desolate kingdom was overtaken by the corrosive magic, inhabited only by possessed machines. These contraptions built more of themselves out of the corroded kingdom, while the city itself seemed to become self-aware, destroying any living being that attempted to come near it. This mechanical amalgam became known as the Kightmare, a blight among machines. Soon after, a group of its drones discovered the sky temple, where the Talonians resided. Seeing them as a threat, given their advanced technology, the construct escaped the underworld, and traveled to the temple. Ra, being in conflict with Cthulhu himself, was unable to aid his worshippers. From there, the massacre began. The warriors of the Talonian race defended the temple, while the more intelligent ones were sheltered within. Those who suffered a quick death were the lucky ones, and one by one, the numbers of the legion fell. Inside the temple, the other Talonians worked furiously, attempting to find a way to stop the machine. They began to build a construct of their own, which they hoped would be strong enough to combat the terror. They ran out of time, as the Kightmare had breached the temple, slaughtering the last of the race, all except one, who had survived the machine's wrath. Overtime, the corroded kingdom grew dormant in the underworld. But should the desecrated temple ever shine again, it would waste no time in finishing what it started...

Cthulhu's Organs
When Cthulhu was finally slain, Ra realized he would need to create strong creatures to aid in defending his peaceful world. He started by reanimating cthulhu's heart and brain to keep watch over the Crimson. He then reanimated one of Cthulhu's eyes to keep watch over the peaceful people of his planet, and to crush anyone who dared to defy him. However the eye soon became a legendary beast thought to be of malevolent intent and they soon set their eyes on defeating the beast.