So basically I decided that Eddie and Will bond over being dead and then being brought back to life. Now Will isn't the only zombie boy in town and he's glad there's someone who understands him. Eddie on the other hand is just glad that Will no longer has to feel alone, because imagine being the only zombie in your town and holding onto that guilt.
This isn't a post about how they bond over that, no, it's about how they bond over that and defeat Vecna together, following the Kas theory. I think vampire Eddie is bound to happen, there are many hints towards it, plus it would just be really cool. And obviously you can't just have a vampire roaming around, so Vecna takes him in and kind of "turns him to the dark side".
Will, on the other hand, is still living in Lenora when he starts having Vecna symptoms again. He has this "oh fuck" realization, but him being the anxious little teen he is, he decides to hide it. Eventually, Vecna just kidnaps Will and forces him into the Upside Down.
So now there's the three of them in the old Creel house in the Upside Down. Eddie got used to it. He drinks demorat blood to keep himself alive. And imagine him just sitting at the dining room table, drinking from a goblet to feel fancy, and then Will walks in with Vecna. And oh boy does Eddie recognize him from all Mike's ranting. 'So this is the boy Wheeler has a crush on?'
And Will has no idea who Eddie is because he just got abducted from California. But he looks human, right? So he sits next to Eddie at the table, but then gets a closer look at him. His eyes are red, but not in a high way, in an abnormal way.
"So, you know Mike Wheeler, right?!" Eddie asks excitedly. Will's eyes widens. This weird looking guy knew his friend. "So, I take it you died?"
"I mean, kind of. Years ago."
And like that, they bonded. They talked for hours and eventually Vecna just let them be. Will found a comfort from an older man who wasn't Jonathan, and Eddie (who always hung around kids at school) knew how to keep the conversation going with a smile.
But the real question is how did they communicate with people in the Right Side Up and overthrow Vecna?