I think I came away from The Old Guard somewhat disappointed. I'd seen the effort that Charlize Theron put into fight training, I'd seen the stunt work, I'd seen the concept. I just though there would actually be more to the film. What's there is fairly enjoyable. Greg Rucka isn't a bad writer, but perhaps he was too in love with his own concept. I felt like the movie put more effort into setting up sequel concepts than developing this film.
It's a fairly standard action movie about ancient immortal warriors who can't be killed... until they can. Eventually their time is up, because of... reasons. Then they stop healing and die for good. It's Highlander-esque in minor ways, but mostly concentrates on the idea of the warriors already somewhat disillusioned with continued existence and their fight to make the world better using their ability to... well, I guess just kill people. Eventually there's some contrived reasons about the magical nature of their actions having echoes that better mankind, but it's a little thin.
Really, much of the plot is thin. While the "finding a new immortal and training her" aspect seems promising and mostly works, it also felt abbreviated. Meanwhile, the antagonists' plot mostly just seems cliched. The big bad guy is a dickhead pharma entrepreneur with delusions of creating human immortality. Chiwetel Ejiofor is a rogue CIA operative who serves them up to our pharma bro and then has a change of heart by movie's end. That's a problem too: it doesn't feel like most of the characters have thought through their motivations. The CIA agent has apparently discovered the secret history of these immortal warriors, meaning he knows their importance and the good they do, but gives them up to have them vivisected for a potential cure for death because of the flimsy excuse that he watched his wife die, immediately changing his mind when he stops to think about it for a second. None of it makes much sense, but it's mostly a list of excuses for action scenes. Which there aren't as many of. I thought it'd be more John Wick-like in its abundance of action, but it can often get talky in the middle, particularly as the other immortals poorly explain their existence to their newest member.
But being amazing wasn't a prerequisite for finding this entertaining. You can't fault Charlize Theron for much of anything. Her ethic for training and making fights look good is beyond reproach. If this doesn't prove that to you, watch Atomic Blonde instead. The rest of the cast is well-played, but none of them feel like real people. They're actors delivering dialogue and exposition, not characters with lives outside the scene. It just needed more for everyone to do and to probably develop everyone a bit more, as - by movie's end - they still feel like strangers and the bonding that's taken place feels undeserved.
Sometimes, you just want a fun action flick instead of another dreary, deep drama or brooding horror film and, in the midst of a pandemic, big action films are hard to come by for the moment. If this doesn't suffice for a bit, perhaps your standards are too high.