We have a new Swamp Thing … for now (Spoilers)
The ongoing crossover Endless Winter has been a bane and a boon for the Justice League and it calls forth a new Swamp Thing to even the odds a little bit. This is why we are getting a new person to take over for Alec Holland as Swamp Thing.
This is an old time called the Viking Prince who was summoned back by Queen Hippolyta. The man was summoned to provide input and help in beating Endless Winter and the Frost King.
The other half is the Swamp Thing power and element per se. Wonder Woman visited the afterlife in an attempt to bring back Holland but the latter refuses and instead gives her a piece of the Swamp Thing husk which can bond with anybody Diana wishes to become the new champion of the Green aka the Parliament of Trees.
And when she gets back from her adventure, she sticks the power which transforms the Viking Prince into the new Swampy.