Related Clues:

• Most pitch-black
• Black to the max
• Most wicked
• Most vicious
• Least good
• Most villainous
• Most murky
• Superlatively spiteful
• Most hateful
• Most baleful
• Closest to base?
• Like the darkest night
• Supremely beastly
• Most stained, as from a leaky pen
• Most blackened sink, i.e. stained inside