"Avenging Spider-Man" #21 by writer Chris Yost and artist Marco Checchetto is the second part of a two-part tale in which Spider-Man (or rather, the current Spider-Man) teams up with a selection of the movie Avengers cast, including Black Widow, Hawkeye and the Hulk -- although "teams up" might be a strong way of putting it, given the limited nature of their interactions.
Once a fairly straight take on a team-up series, the current appeal of the "Avenging Spider-Man" largely lies in seeing characters having their first team-ups with Octavius in Peter's body. With that in mind, Yost has crammed multiple extra characters into this story. Unfortunately, that doesn't leave them a lot of room to do anything. The Hulk has a reasonably major role, but Hawkeye, Nick Fury and the Black Widow seem almost interchangeable. If those characters are going to make a gratuitous team-up appearance, at least give them a story that has a reason for them to be there!
The Chameleon's appearance is considerably better-managed (it actually makes use of his specific skills, for a start), although it doesn't seem clear why Otto is interested in him. At first it appears as though it's an opportunistic act, but the final scene suggests that he's actively collecting old Sinister Six members for some purpose. Either way, it's all a bit vague and readers will have to trust that it'll be explained later, something which suggests a (not entirely welcome) change in approach, moving away from the previous one-shot format of the book.
The other villains, The Saints, are only vaguely sketched-out as far as these things go. At the moment, they're little more than visuals and a power set, which is rarely a good situation (although it can work -- just ask Ghost Rider!). It seems that Yost is planning to develop them more, but as a reader it's hard to get engaged with the somewhat confused combinations of character elements (part-religious zealot, part-zombie, part-Russian agent). Mostly, it feels like they add very little, and perhaps the comic would've benefitted from being reworked as a Chameleon-only story.
Checchetto's pencils are moody but fast-paced, with a wide variety of layouts and storytelling devices employed in the issue. It's never less than good, successfully elevating what could've been an otherwise dull chapter in a longer story, but the colour palette of gloomy reds and blues (while a clever idea for a Spider-Man comic) seems to overpower the pencils and de-emphasise the storytelling. It's not a bad job, but it does feel like a bad fit for the story. If anything, it does more to emphasise the Hulk rather than Spider-Man, since his appearances are more or less the only green in the issue.
For the most part it is a technically competent book, and even when Yost isn't so strong on plotting the characters and dialogue are enough to remind you of his abilities -- but for a title already struggling with its identity (no joke intended) it's just as well that it's heading for a relaunch. It appears to have become just another ongoing monthly Spider-Man book, and that was the very thing it was always intended not to be.