I don’t know much about the Green Lantern universe either. I follow Marvel way more.
I knew the ring had to be recharged in order to be used, but I found it weird that Hal made John go fetch his lantern. I thought he’d say a few choice words and the lantern would magically appear.
Koop, if you watched Ryan Reynolds’ Green Lantern movie, one of the villains was Sinestro, who was locked up in Episode 2.
I don’t know much about the Manhunters either. I used to watch Supergirl, which was part of the Arrowverse, and Martian Manhunter was really the only “Manhunter” I knew until they introduced the female version.
Supposedly, from what I remember without looking it up, the White Martians killed off almost all of the Green Martians, leaving Martian Manhunter as the last one of his kind. So I’m guessing they’re changing the origin/storyline from the Supergirl TV show?
And I just looked it up to make sure I wasn’t completely remembering it wrong. In Supergirl, the White Martians were indeed responsible for the genocide of the Green Martians, and J’onn was portrayed as one of the last surviving Green Martians.
One important thing, though: the Manhunters in Lanterns are not Martian Manhunter or the White Martians. They’re an entirely different thing ancient synthetic/robotic beings created by the Guardians before the Green Lantern Corps. So Lanterns is introducing the comic-book Manhunters, while Supergirl was dealing with Martian Manhunter (J’onn J’onzz) and the White Martians.
So your confusion actually makes a lot of sense. DC basically decided, “Yeah, let's have multiple things called Manhunter.”