When trying to come up with possible reasons why Bloodshot exists, it's difficult not to descend into cynicism. This is a movie that seems designed to cash in on a dubious combination of copy-catting Marvel and DC's successes on the big screen, and Vin Diesel's modest star power, which can potentially draw the same crowds who flock to each new Fast and the Furious movie (including us). And Bloodshot isn't a completely worthless imitation--it smartly leaves a lot of the original Valiant comics' cheesy trappings (white skin, red chest, red eyes) in the past where they belong, and it's built on a really fun (albeit moronic) sci-fi conceit that brings with it plenty of cool visual effects and inventive action set pieces.
But those are all things we've seen before at the cinema, and Bloodshot does little to set itself apart from the last 25 years of superhero movies. It's a supremely stupid movie, in the very literal sense that it rarely, if ever, makes any sense--the kind of movie that begs you over and over to simply "turn off your brain" and enjoy the machismo spectacle. But idling your brain low enough to "enjoy Bloodshot for what it is" might do permanent damage.
Vin Diesel's Ray Garrison is a soldier who, when he's not taking out bad guys and rescuing hostages all over the world, savors picturesque romantic getaways with his beautiful wife. Of course, things are actually a lot more complicated than that, but the movie takes a long time to get to its big "twist." In case you want to go into this movie completely blind, I'll mark this as a spoiler--but everything discussed here is explicitly laid out in the trailer: Garrison is actually an unknowing operative of a private paramilitary corporation that repeatedly implants him with false memories of his wife being murdered in front of him, then sets him loose on what he thinks are vendettas but are actually assassinations. They wipe him clean every time, tweaking and tuning the fabricated memories and their own performances as they prepare to sell "weaponized revenge" to the highest bidder.
On top of that, they've replaced Garrison's blood with billions of "nanites," microscopic machines that lend him superpowers and can repair any organic damage to his body in a matter of seconds. "Project Bloodshot," as he's dubbed, is like Wolverine on even more steroids; a meathead with a cybernetically enhanced heart of gold. Diesel is, naturally, perfect for the role, and he manages to squeeze in a dimension of vulnerability to the character that makes him likable in spite of everything.
Bloodshot's lengthy opening act as it builds toward the reveal is almost unbearably stupid--and, admittedly, deliberately so. Once it gets there, the idiocy takes on a different tone. Bloodshot cribs liberally from a wide variety of better movies, starting out in the realm of 1992's Van Damme and Lundgren-starring Universal Soldier, before eventually transforming into more of a knock-off MCU by way of later Fast and Furious movies, with a hint of Groundhog Day for good measure.
Diesel is surrounded by an able cast doing their best with dopey dialogue and scenarios. Eiza González, Sam Heughan, and Alex Hernandez portray the other members of Garrison's "squad," each with their own, fun cybernetic enhancement. González's character KT, for example, breathes through an aperture installed in the center of her chest, rather than through her trachea and mouth.
To give you an idea of how dumb Bloodshot truly is: When, at one point, KT's breathing implant briefly stops working, the character spends a few moments in the aftermath gasping for breath--through her mouth. That's not even mentioning the fact that although the movie could use KT's condition as a thin excuse to explain why she dresses almost exclusively in revealing, skin-tight crop tops, instead it just doesn't even bother.
Guy Pearce is the man in charge who orchestrates the whole scheme, although he never really sells his character's villainy. Siddharth Dhananjay (from Amazon's excellent rotoscope-animated Undone) plays the chief developer behind the Bloodshot tech, though he mostly exists to have several jokes made about his apparently small penis, and so he can get one-upped by the superior hacker Wilfred Wigans, played by New Girl's Lamorne Morris. Wigans is the source of most of the movie's genuine laughs, and Morris at least seems like he's having fun, even if most of his gags, like trying to speed-eat Chinese food while action scenes happen around him or talking to himself while doing generic hacking stuff, are essentially nonsequiturs that have little to do with the other characters or what's actually going on in the movie.
Most of the characters' motivations are, at best, unclear; at worst, they seem to actively contradict those characters' personalities and/or stated goals. The whole movie operates under the weird conceit that there are no real consequences for anything that happens; this private group is orchestrating hits all over the world, causing large-scale destruction everywhere they go, but there's never any discussion of collateral damage, innocent bystanders, or intervention from any form of government. Granted, that would definitely detract from the fun tone Bloodshot most often goes for, which it does occasionally achieve in isolated moments of blockbuster levity.
The nanites themselves provide plenty of fodder for cool visuals and effects. There are even some elements of body horror as Garrison sustains increasingly outlandish wounds, like getting half his face blown off, only for the nanites to swarm there and reconstruct it as we watch.
Bloodshot might not be entirely faithful to the original design of the comic book character (and I'm glad that Vin doesn't have a big red circle in the middle of his chest), but there are some nods for fans. The nanites burn neon red when they're doing repairs, causing Garrison's chest to light up like a blood-tinged Iron Man. In one scene, Garrison gets covered in flour, causing him to appear ashy white, which feels perfunctory. Later, once he gains better control of the nanites, his skin turns white as if drained of blood when he's concentrating them on specific tasks, which sometimes involves sending them out of his body entirely. How he continues to walk around when that's happening is as much a mystery as any other choice in this movie, like how nanites that repair your flesh somehow turn you into a walking tank who takes bullets to the chest without so much as flinching.
If you're asking these questions--as I did--you've already overthought Bloodshot. If Vin Diesel and a goofy sci-fi/superhero mash-up premise are enough to get your nanites pumping, then by all means, enjoy. Otherwise, Bloodshot will simply leave you cold.