>>92744116it was explained in that series
the green said "fuck, we dont have an avatar" and played by the rules, they "cloned" alec holland and used him. this was basically morrisons swamp thing. Then when he turned out to be shit and died, they said "FUCK, now we dont have an avatar AGAIN" and broke the rules that the kingdoms use, resurrecting what was left of the real alec hollands body, that they spent the time morrisons was out doing shit, fully repaired
this made the rot go "man, fuck those cheaters, we're resurrecting arcane"
blah blah blah plot plot plot, arcane is an asshole, and at some point alec (resurrected) needs much more help from the green, so he enters it, and eventually comes across the avatar before him, Alec (morrison) who they only draw in blue tones, and refer to as the plant that thought he was a man
the green never told "morrison" alec, he was a clone till he died, so he thought he was alec holland who never died.
its confusing, and like nearly everything new52, they pick and choose what is canon, and dont really talk about the rest, because its safer than saying "no, this shit isnt canon at all"
the short canon was
alec holland was born, and then died at the hands of arcane, before he became swamp thing
"alec holland" was born into the role of swamp thing, and eventually died
alec holland is resurrected and is for the first time swamp thing
in the new52, every time its "alec holland" after the reveal he was a separate person, he's the one pictured in blue, and alec holland is the normal green