he has slight control of the venom that flows from his body 

Denmark: I don't mean to harm or kill anyone...

theories state that Denmark was the source of the creation of the Great Injustice Curse the reason that the young princess died along with the thirteen other lost souls due to his highly toxic venom that has no cure and is thought to be a terrible illness ( so Christopher is fine!) 'he must have felt threatened when he entered Voodootale during that time and accidentally killed those lost souls that died that day 'Denmark felt to scared to show his face to anyone that's why he got away with murder and made it seem like a curse that's why he fears Voodoo! he fears that Voodoo would harm him or... he would accidentally kill Voodoo due to the toxins in his body' (that's why hes suicidal and thinks of himself a plague that was made to destroy the multiverse and curses at the humans who made him)