While finding the overall plot awkwardly delivered and lacking development, James Beckett praised Ton Baileu as the main heroine, the male cast having solid rapport with one another and the action scenes they take place in, concluding that fans of otome video games will enjoy it.
Theron Martin praised the execution of a "pretty straightforward reverse-harem premise", highlighting the characterization of Ton and her male harem, and both the animation and soundtrack that culminate into "a respectable production effort."
[5] He also gave praise to Ton's leading presence carrying the show, along with the supernatural worldbuilding involving its cast of Twilights but found criticism in the off-model character art and a "general lack of complex, impressive animation" outside of the art direction and a few "battle-heavy" scenes in the final episodes that are hampered by lackluster villains, concluding that, "Even though most of its individual elements are pretty mediocre, Phantom in the Twilight isn't so difficult to recommend - there's enough strong material in here to elevate the show to "pleasant surprise" status, a good-enough romp worth watching if you have a craving for sexy supernatural boyfriends, and want a series that likely won't disappoint you.
"[5] Conversely, Allen Moody from THEM Anime Reviews was critical of the Twilights' durability and nonexistent "sense of peril or concern" for their own safety, the "less elaborately choreographed" battles and Ton's story being "overused" from other vampire adaptations, but commended the series for its "attractive character art" and highlighted Tauryu and Wayne as "particularly interesting" amongst the cast, concluding with: "I just never got as emotionally engaged by the show, or its characters, as I would have liked, and I almost feel guilty about that; I really wanted to like this show more than I did.
"[6] Silverman placed the series at number three on her top 5 best anime list of 2018, praising the action-harem plot being carried by Ton's no-nonsense characterization and the male harem having distinct personalities from each other, concluding with, "Add in some nice attention to folklore and literature, and Phantom in the Twilight becomes the reverse harem show for people who don't like the genre or who want to see it do something new.