Dragon Ball Z Movie 13 Wrath of the Dragon is a story focusing on Tapion, a legendary warrior from the past who was said to defeat Hildegard. We also see some of that in a flashback.
He was sealed in a magical box that can't be opened by force but only through special means which the Dragon Balls found use in this film.
We would find out the reason why Tapion was sealed and his connection to Hildegard, a giant Kaiju sized monster that is even stronger than Ultimate Gohan.
The objective is to defeat it obviously, but that isn't where the movie shines.
It is also one of the few Dragon Ball Z movies that can fit into the main timeline, about after the defeat of Majin Boo.

It has humor and some horror elements because of what kind of creature Hildegard is.

The thing that makes the movie great is Tapion's character, his backstory and him trying to cope with his issues. On the surface he appears like an angsty teenager, but doing so is excused with his relationship with the villain.

Hildegard himself is not a character, but just a monster that destroys. A phantasm created of all evil of Tapion's planet and magic. It consumes live forms to power itself up when it takes a break from destroying shit like monsters are. How it consumes others is scary as shit.

Trunks really profits in this movie. Dragon Ball Z anime, Dragon Ball manga, Dragon Ball Super manga, Dragon Ball Super anime, Dragon Ball Super movies and all the previous Dragon Ball Z movies he started him he was pretty much a filler character played for gags. This is the first time he is treated like a real character. His interactions with Tapion feel believable and showed a part of him that isn't just Goten's friend that makes Gotenks. He also managed to get through Tapion and make him feel more comfortable around him. So this is the only place besides Dragon Ball GT where you can see present Trunks feel like an actual character.

Bulma is also pretty good in this movie and gets some very good interactions with Tapion where they talk about Tapion's issues and she works to help him. Bulma doesn't get a lot of good moments in Dragon Ball besides being a plot device, fan service or comic relief, so that is a welcome change of pace for once.

Hui is an interesting antagonist. He seems like another Babidi on the surface but he is more involved directly, isn't scared off others and is far more manipulative without the need of magic.

I do have some Criticism. Shenron grants only 1 wish instead of 3 but this can be overlooked for the sake of movie runtime.
Normally I would praise characters with different shapes and sizes, but the fight against Hildegard just isn't interesting. Mostly because every character can fly and this leads to a boring choreographed fight where a certain character just charges at a body part and Hildegards response is usually to slap him/her away.
The only exception may be when Gohan first fought part of Hildegard where it used its tail in an interesting way to get up and Gohan low kicked him.
Nowhere as fun as watching the fight against Lord Slug, Oozaru Vegeta or Oozaru Baby.
The use of other characters was also meh. The Dragon Ball hunt was fun to watch and seeing Gohan and Videl work as Saiyaman and Saiyawoman, but many characters who fought against Hildegard just didn't feel like they needed to be there.
Goten was a waste in this movie and only existed to power up Trunks. Vegeta exist for fan service too.
The way ending of Hildegard also feels questionable with something that was never foreshadowed and can come off as an asspull.

Overall it is a ver enjoyable movie. Tapion is a fan favorite and despite not getting a fight he is demanded by fans for any Dragon Ball fighting game. Goku uses the Dragon Fist in this movie for the first time, a fan favourite move, and sparingly used in Dragon Ball GT in the most epic ways. The animation and soundtracks are top tier. Even without amazing fights, the great storytelling and the great use of tone is where the movie shines.
It is highly recommended to watch this movie.