"Alternate versions of Spider-Man from multiple dimensions are gathering on Earth, looking for strength in numbers while staying one step ahead of their pursuers - a family of Spider-eating Inheritors. As the Spiders flee from the Inheritors, they find themselves up against the Sinister Six, who are wielding a powerful, Spider-fueled machine capable of altering the universe. Faced with becoming food or fuel, Superior Spider-Man and Ultimate Spider-Man join the fight!" — Chapter Briefing
The only way to recruit Ultimate Spider-Man is to complete the list of Tasks.
One of the Tasks requires the defeat of an Epic Boss. This can be done by having the requirements needed to unlock the Epic Boss or by skipping the task by paying 30 Gold.
The requirements are:
There's a dimensional portal holding open here, with some kind of creature coming through. Get a hero there to find out who or what it is. It doesn't look like an Incursion, but we can't tell for sure.
"Spiders from other dimensions are appearing all over the city, while an Inheritor roams the streets, searching for Spider-Totems. Some days, you actually hope it's just a Mysterio-induced hallucination." — Mission Preview
It's apparent that every dimension and timestream has its own Spider-Totem. At least we think it's apparent. Angela has a foot in several Asgardian realms. Perhaps she can find out for us whether there are Asgardian Spiders.