A conceptually interesting movie, that fails in its tone, pacing and believability. The fight choreography is competent but sadly adds to the aforementioned problems.
The initial tone might make you expect a comedy, something light-hearted or maybe a "dramedy". Characters are introduced as seemingly goofy and useless. I assume it's done to subvert expectation and surprise viewers with the coming events. The idea seems good to me, but isn't executed to best effect. The first 15 minutes made me feel like watching an episode of a very generic TV series with failing humor, but somewhat intriguing characters.
Once the action begins, everything seems a lot more promising. The fights favor flashiness over authenticity and there's a few too many edits, with the camera jumping around, mid-action. Yet, the action looks fairly good, featuring decent movie martial arts, and all moves are readable despite the editing. It's fun to watch, at least for the time it stays believable. Here's where pacing and plausibility get in the way, though. On a very theoretical level, it might seem sufficient to just have a well choreographed fight sequence, for entertainment. Like a boxing match or MMA cage fight. That works in sports for a couple of reasons. The primary one probably being that the specific audience has an interest in that specific type of fighting style. In a movie, it's generally smarter and a lot more efficient when the individual fights themselves tell a small story that the viewer can relate to, rather than just to have a fight where opponents exchange blows until winner and loser are defined. Jackie Chan understands this element perfectly. His choreography always has more to get invested in and it's not exclusively humorous.
The Age of Blood does little to make the fights relatable and takes a clumsy approach at trying to create tension. It's putting all of its weight onto the assumption that the audience wants to see the underdog win. That concept loses impact when there are sequences where you might be left wondering why characters are even fighting, when there were reasonable options to avoid conflict. After several of those incidents, the movie begins running on empty. The protagonist's motivation is so unclear that he even questions himself, at some point. And the story does not have enough substance to support repetitive action without tension.
Considering how the movie starts, character development could have been a saving grace. But although we learn more about the characters, they never seem to change along the way. What's left is a sequence of decent action scenes with lacking focus, intriguing characters played by competent actors and a thin story, based on real events. Enough for some mild entertainment, but hardly memorable.
Props to the stunt/action team, including all participating actors, though! They did great work for what I assume was a relatively low budget.