My idea's

Just to be clear anyone can use my ideas as long as they don't say it was theirs

*Black-Beard kills one of the brethren court lords and steals their territory

*Black-Beard steals the notebook gem thing from the last movie in the series

*Black-Beard does a ton of crimes and frames jack sparrow

*Black-Beard does a ritual to make mermaids fall in love with him at first glance or any type of female, then he takes all their tears to get a lot of years by making newborns drink the water, therefore getting another 100 years easy