Joel is the Grim ReaperTo be fair the first time he appears in astral form he's posing as him.
Joel is the AntichristIf you can't accept that he would really kill and/or ruin so many people just to get revenge on his brother.
Joel isn't really evilHe has just been corrupted by his sister into getting revenge at all costs
Julian is the true villain of this comicFor all we know he'll make Joel look like a good guy.
Artie will turn out evilHe might have recently destroyed a small city and killed over 500 people, plus Melusine has come back as a ghost and might be influencing him
Joel is Zalgo
Everything out of the norm didn't happenThe comic would make a lot more sense if it turns out all the rape and pregnancy and ghost sisters and murderous sea-mammals turns out to have all been a dream, and that it really WAS just a bunch of talking animals working at a wacky movie theater.
Lorelei will finally seduce Matt. Father Tim will be raped by Chelsie. Nicole will finally score Cecil. Thonnen and Naomi are descents of the Animal Christ. Lorelei, Joel, Miranda etc. are descents of Anti-Christ. Artie is incarnation of Krishna.
Matt is the one responsible for everythingHe is clairvoyant and is changing the future in order to change himself, so he becomes more content after rejecting Jeremy.
Matt is a Time Lord
Joel will lose control of his powers, plunging the world into darkness
All of Joel's efforts aren't actually to get revenge on his brother for killing Miranda.What he's actually trying to do is create a bridge in space-time so he can cross over into the Furthia High universe and have hot mansecks with Campy, it's totally true.
Joel started starving himself and later encouraging Matt to engage in S&M/body-mods with him to feed his sister's spirit.It's confirmed that Miranda feeds on pain and suffering. The pain Joel feels while getting a tattoo/piercing/branding might hold her while he fits the next part of his plan together. Matt stopped Joel from starving himself, so he needed another method which Matt wouldn't stop, so he pretends it's merely experimentation and possibly psychically nudges Matt to be more open to it (though, if Matt's dreams in the guest strips are canon, he may not need to).