The earliest known purpose-built weapons in human history date to the Bronze Age. Maces, which were little more than rocks mounted on sticks, had questionable value as hunting tools, but they were superbly suited for smashing the bones and skulls of other humans.
These are by far and large the most horrific, dangerous, violent, and most powerful weaponry humanity has ever came to conceptualize. Each WMD is terrifying in their own rights.
Nuclear weapons or radioactive weaponry are more of the destruction side. You have a entire town of people and then boom! the entire town is just gone and everyone in it who have somehow survived the initial explosion would be blinded and then poisoned with toxic nuclear waist which will give you commonly a grizzly death and one many would fear to experience.
The largest nuclear weapon ever dropped was the Tsar Bomba from the Soviet Union in the 1960’s with a payload of 50 megatons that’s equivalent to thousands of Little-Boys and Fat-Man, which are the two bombs dropped on Nagasaki and Hiroshima alike.
Next are chemical weapons. They’re the most brutal of the three. People were “mutilated” inside out of their lungs and air canals by mushroom gasses that burn and mold through your lungs and makes it seem as if you smoked 20 packs of cigars a day.
It can make people cough blood, and eradicate humans in horrors we don’t wanna imagine. Look up Agent Orange or mushroom gas victims to truly see the terror that chemical weapons can process.
Then finally, biological weapons, the biggest killer of the three. Slow, painful, and in the end, causes ruin to all. The Black Plague which killed 1/3 of Europe and resulted in hundreds of millions of deaths was possibly a biological attack orchestrated from the Mongols.
It’s by far the most simplistic and ugliest put of the WMD’s. Something as simple as throwing corpses over walls and such is considered biological warfare. It’s the most dangerous out of the three because of its simplicity and how easy it is to orchestrate its creation.
Advanced biological weapons might be able to cause mass pandemics that can guarantee an almost End of The World scenario. Slower to process its destructive potential then nuclear weapons? Yes. But it’s arguably more deadly then even nukes can process.
Those are the most horrific weapons humanity has created. We call them Weapons of Mass Destruction for a reason. Super-weapons that if used correctly can end entire civilizations with a few attacks. These are horrifying weapons that are so deadly that their usage is banned in war. It’s the biggest war-crime to use such weapons, and be glad it is.