Dementia was one of the cousins of the Sisters of Death with currently unexplained origins. Her hands were coated in mud that caused suicide and depression.
Dementia was very likely just as twisted as her fellow Sisters, and likely believed life to be a sin.
After the Sisters found a vessel connecting Deadworld to Mega-City One, Dementia and her sisters began to cause wide spreads chaos. She caused massive waves of widespread depression leading to hundreds of mass suicides. Dementia and her Sisters are defeated when Judge Anderson and Judge Shakta destroy the bridge, trapping them in Deadworld.