Based on the four-part miniseries included on Blu-Rays of That Time I Got Reincarnated as a Slime’s second season, Visions of Coleus is set at the beginning of the television series’ second season. Everything here takes place before Rimuru’s ascension as a true Demon Lord—that is, before the attack on Tempest and the subsequent revenge massacre of 20,000 people. This means that, at this point, Rimuru, while still powerful, is not the unstoppable force he will eventually become.
Honestly, this is a welcome return. There are forces in this story that Rimuru would not be able to defeat in a fair fight—and even more that would push Rimuru and his friends to their limits. As a result, there’s a bit of tension in the story as Rimuru has to use stealth and trickery instead of raw power to uncover the mystery of what’s going on in the Kingdom of Coleus.
The greatest strength of this ONA is the way it subtly forces Rimuru to acknowledge his past in a way he hasn’t done since his reincarnation in the fantasy world. When he came up with an alias for this stealth mission, he chose another name that he would definitely respond to, Satoru—that is, his name from his first life. He then meets Princess Zenobia, who can see the form of a person’s soul. While this primarily allows her to know whether someone is good or evil, in Rimuru’s case, she sees people before her death on Earth. So when he became”The Great Phantom Thief Satoru” for his mission, he chose not to be like Shizu but to be more like an idealized version of his original self. For the first time in years, he’s back in his old body — and still trying to help others like he did back then.
This ONA also benefits from a reduced cast. While Souei and Benimaru have roles in the final act, much of the story revolves around Rimuru and a new group of characters. Without having to let every member of the TV anime’s vast cast have their moments to shine, we’re rewarded with a much tighter story—even if it’s one with some problems private.
Although the general story is quite easy to follow, many viewers will not understand some parts of this ONA. This is because at its core, this ONA doesn’t feel like it’s intended for viewers of the TV anime but rather for readers of the original novel. Both Luminous Valentine and Violet are main characters in upcoming events. Knowing their goals and motivations puts their actions into a context that anime-only viewers won’t have at this point — which can make the story feel difficult to explain. strangely by the time the final credits roll.
Furthermore, the appearances of both Violet and Luminous Valentine are added to the story. Everything was set when Rimuru first met both characters. So they can’t meet each other in this ONA — meaning the story has some convenient contrivance to ensure that they don’t. Honestly, it seems a bit forced that this leaves Rimuru, Souei, and Benimaru waiting patiently inside an opaque bubble (which Rimuru can escape from easily) with nothing but a corpse company for a few minutes while Luminous Valentine and Violet tried to get going.
Overall, Visions of Coleus is a serviceable little story about That Time I Got Reincarnated as a Slime side story. While those who read the novel will get more out of it than those who only watch the anime, this flashback to an earlier time in the larger story provides a solid mystery with plenty of twists and turns. If you’re invested in That Time I Got Reincarnated as a Slime, there’s no reason not to check this movie out.