|These are all my reaction|
In Supernatural, Rowena, Crowley's mother, has made a bargain with Sam Winchester to translate
the book of the damned in exchange for Sam killing Crowley. Sam struck the bargain to save his brother Dean from the effects of the mark of Cain, which is slowly turning Dean into a demon. The spell in the book of the damned will cause a great tragedy if it is used, so Dean refuses to use it. So Sam has been working on it behind dean's back.
On top of all of that, a family called the Steins is hunting for the book that they used to possess eighty years before. They used the book to cause tragedies like world war two and the hundred year war. They used to be called the Frankenstein family before they had to go underground after Mary Shelly saw their genetic modifications of extra muscle and two hearts. One of them goes after a friend of the Winchesters',, Charlie thinking that she has the book and ends up killing her. Before she died, she was able to crack the code of the book and send it to Sam and Dean. Although Dean will be much more reluctant to try the cure after what happened to Charlie.
Homestuck is a slightly better story, since Cal, the creepy puppet that has been a mult-iuniversial constant since the beginning, turned out to be a seed for bringing Lord English into universes at their ends so he can destroy them. As a giant time traveling skull faced god, he is rather intimidating and tries to fight with the heroes of the story. The heroes must tie his soul to the doll to win the fight, along with a version of one of the heroes, Dirk, and a troll named Euqius.
All of that was communicated through bad claymation by the ultimate villain. Ah, yes, that was worth the gigapause, definitely. It is, however better than the timeline where everyone except Roxy and John died off in a pretty terrible way, considering that they are mostly god tiers, who can only die heroic or just deaths. You would think that they would be less heroic and temporarily evil.
The major difference between the timeline where nearly everyone died and the one we are currently in, is that Vriska is still alive. Although she is my patron troll, I did not like her for most of the story, probably because of the occasional murders and maimings, but I actually sort of like her now. Plus, if it means everyone is alive and have cut the garbage and Davekat is canon, I am fine with this change of events. In a recent update Dave and Karkat were analyzing all of Johns feelings.
So that is what has been happening in both of those fandoms.