Black Mercy - Krypton: Season Two

An unstable species of parasitic flora discovered by Val-El while illegally travelling and exploring space, the Black Mercy was a powerful and dangerous organism. 

When affixed to a host, burying its roots into their brain and nervous system, they can create hallucinations so vivid that the victim believes the alternate reality they witness is the real thing. The only way to overcome the effects of the plant is to actively reject the hallucination, something that very few people had the strength and willpower to achieve.

Experiencing Black Mercy first-hand during his own travels, as someone from the future, Dru-Zod believed it to be an ideal weapon of choice in his arsenal; concluding that few people had the perception to see through the illusions and even fewer had the willingness to give up on their fantasy world to return to reality. 

In the unlikelihood of being removed from the host, the parasitic organism left a residual - non-lethal - virus in their system that required the application of Hantha root for complete recovery. 

Stolen from El's Fortress of Solitude by the ruling general, after organising a military coup d'état, he used samplings of the Black Mercy to overpower and sedate his disapproving mother, Sagitari commander Lyta-Zod. Placing her in a medically induced coma, he kept her a secret from the rest of Krypton, deploying a clone to perform her regular duties and ensure the continuation of his authoritarian governance. 

Months later, wishing to weaponize the invincible killing machine, Doomsday, Zod ordered his chief scientist, Lis-Ser, to extract the plant's naturally produced toxins and inject them into his bloodstream. Successfully seizing control of the rampaging beast, he soon turned him loose on The Rebel forces located on the nearby moon of Wegthor, wiping out the majority of their troopers in a full-on assault on their headquarters. 

Ser considered the half-life of the toxin to be "limitless," with Zod reasoning that anyone exposed to a pure dosage could be under its influence permanently if not treated. Even a being as strong as Doomsday, "the mythical beast of the Outlands," fell under its influence, with little resistance, at least enough to keep him in a susceptible and suggestive state. 

However, this inadvertently led to Dru's downfall after the Black Mercy, damaged by the repeated toxin extraction, began to lose its hold over Lyta. Escaping from her six-month-long psychedelic dreamscape prison, she believed that it was the only way to detain her son without using lethal force. Fearing he would only escape the Phantom Zone and wreak havoc on the universe if they sent him there, both his parents, Seg-El and Lyta, ensnared Zod with the vines, promising that they would keep him in a comatose state for as long as necessary to one day rehabilitate their lost child.