Eradicus, a Sith Lord of the New Sith Wars era, functioned as an apprentice to Darth Ruin, the Dark Lord of the Sith. This Lord Eradicus was known for donning dark armor, a form of plate armor imbued with the power of the dark side of the Force.
The character Eradicus made his initial appearance in the Book of Sith: Secrets from the Dark Side, a 2012 release. Daniel Wallace, the book's writer, derived the character's moniker from Abel G. Peña, who had originally considered the name Eradicus for the character who eventually became known as Darth Ruin, before discarding it.