Why Is Mahadeva Associated With Wicked Characters

“Lord Shiva takes charge of reforming persons who are ghosts and demons, not to speak of others, who are godly; therefore he is the spiritual master of everyone, both the dull and demoniac and the highly learned Vaishnavas. It is also stated, vaishnavanam yatha shambhuh: Shambhu, Lord Shiva, is the greatest of all Vaishnavas.” (Shrila Prabhupada, Shrimad Bhagavatam, 4.2.2 Purport)