Persona Trinity Soul is weird because the only reason anyone would care about it and the only reason it is even remembered is because it is a weird spin off of Persona 3 that was eventually de canonized. This show isn't awful but at the same time it isn't necessarily great or even that good at times. Here's a mostly spoiler free summation of my thoughts.
Story and Characters 6 - The main plot of the series is about the mc and his little brother moving back to live with his older brother, hence the trinity. The older brother is a cop with special powers and is investigating murders and whatnot about their town. Meanwhile the mc attends school, makes friends, and ultimately gets involved with his brother's work. The overall focus of the show is on the relationship between the three brothers, and this is a mix of occasional good and mostly bland.
The older brother is a very typical cold-hearted individual who doesn't want his family involved with his work and the mc is also typical in his sense of right and curiosity. The most interesting character is the little brother, who has a bit more going on with his personality later on in the series. Aside from the main three the side characters are fairly simple with a few decent episodes dedicated to fleshing them out. Some episodes serve no purpose and are pretty much just filler which holds the show back significantly. The only real connection this show has with the Persona series aside from the titular powers is Akihiko. His presence is fairly minor though, the emphasis is placed on the cast original to the show.
Overall the show itself doesn't have any necessarily bad story elements or character moments, however they aren't particularly noteworthy, and the presentation is relatively bland.
Art 5 - This show is very dated to its time and the animation style isn't particularly noteworthy or impressive. The personas themselves also are foggy and don't look good in general.
Sound 8 - Easily the best part of the show; Persona 3 has a good soundtrack and the show remixes many good songs from the game. Some of the arrangements are on par with or better than the vanilla mixes from the game imo. Aside from the fact they are from the game and therefore catchy, sometimes the music choice doesn't match the scene and aside from the game compositions the rest of the soundtrack isn't particularly memorable.
Enjoyment 5 - Again, the only reason you would ever watch this is if you are a fan of Persona and want to see this obscure show. Even then it is very generic and also boring for most of its duration. Many episodes feel like filler and the end result is underwhelming. At least Akihiko shows up to say hi halfway in.
Overall 6 - Trinity Soul will always be remembered as a piece of Persona history that no one remembers or acknowledges often because it is not that great. Rating this as a show and nothing else it would probably get a 5. The extra point comes from bias and the soundtrack.
