akkamaddi's Simple Cthon
Rare Nether Ore with Unique Properties
In the Minecraft world, there exists a special type of ore called Cthon that can only be found in the Nether. This ore possesses toxic properties and is extremely rare, making it even more valuable than dragonstone.

Mining and Processing
To successfully mine Cthon, a pickaxe of at least level 4 is required. Regular diamond tools won't work here. Among the materials capable of handling this task: onyx from Simple Ores, dragonstone from Netherrocks, Scarlatite and Hephaestan gold from Golden Glitter, green celadon from Simple Cobalt, black silver from Sterling & Black, tenebrium from Simple Arsenic and Old Lace, prasinos from Simple Tungsten, and Cthon ore itself.
Each ore block yields only one mephitic Cthon chunk. Due to its natural resistance to magic, the Fortune enchantment does not work on this ore.

Purification and Item Creation
The mephitic Cthon chunk is too caustic and toxic for direct use. For purification, a simple ingredient not found in the Nether is required - an ice block. A gold nugget acts as a catalyst in the process of turning the mephitic chunk into an elutriated Cthon chunk.
The elutriated chunk can be smelted in a regular furnace to produce a Cthon ingot. From this ingot, a complete set of armor and basic tools can be crafted using standard recipes compatible with most mods that add wood.

Magical Protection
A full set of Cthon armor possesses a unique property due to its resistance to magic. It completely blocks damage from the Wither effect. Although the effect itself continues to work and causes weakness, the player no longer loses health from its impact.