I have a few. The first two are actually novel ideas, but could work as webcomics as well.
#1:
>Vampires, werewolves, zombies, ghosts, demons, faeries, etc are real
>Exorcists, the Church's assassins, hunt them for the good of humanity (most ghosts and faeries are considered neutral/benign)
>Story focuses on Quincy Parker, a rookie Exorcist, roughly 20 years old
>Mother was possessed by a demon when he was young and burnt down their house, killing Quincy's dad in the process and giving Quincy severe pyrophobia, got a life sentence
>Quincy was adopted by Sister Bethany, a close family friend and Exorcist, who trains young Quincy
>Quincy, his training now more or less complete, discovers that he's next in line to be "The Voice", the one human being capable of reshaping humanity's view on Heaven and Hell
>Part of being the Voice is having to go through several extremely powerful demons, each representing one of the Seven Deadly Sins
>Each Prince of Hell has a different human cover
>Lust owns a strip club staffed mostly by succubi, Wrath owns a fight club, etc
>Quincy's friends and allies include Sister Bethany, a gun-toting Exorcist, Francis Lichtenstein, an intelligent/sapient flesh golem, Darcy Dixon, the half-human daughter of Queen Titania, and Mayumi, a medium
>Quincy's primary weapon is a blessed silver baseball bat he calls "Excalibur"
>After losing to Wrath and his hellfire, he makes a deal with Queen Mab to be able to conjure and control faerie ice to protect himself
>Slowly loses his faith in God but doesn't give up the fight, wanting to use his role as the Voice to bring an end to the conflict between Heaven and Hell, and to keep Earth out of the crossfire
>Ends with Quincy defeating Pride and Voicing his plan to God
>God gets pissed and prevents Quincy from going through with his plan and sends an army of angels after him
>Quincy brandishes Excalibur, ready to fight
