Old cover Left. New Cover Right. Which do you think will attract more readers?
View attachment 16116View attachment 16117
The one on the left looks like one of the eruptions that killed the dinosaurs. So if your story is more serious in tone and generally more grand in scope you should probably use that one. The second looks like that thing in anime/manga where someone sees the person they like and the background is filled with flowers, except in this case it is fire works. So if your story is more of a small scale comedy/drama you should use the second, especially if it is also a romance.
The background is "not so good" (or even downright "bad" because it's too REALISTIC = fireworks in nightsky) and the character is beautiful but sadly it doesn't fit with your title, especially >>>>>"DEATH"<<<<<.
I haven’t read the story so I don’t know it’s genera/themes, but I mean, that totally depends on the direction of the story. The cover, as you said, fits as the cover to a romance and/or a shoujo. So, as long as the story is one and the title is justified in context to the story than it doesn’t matter if death is in that title.
Here are a couple ways: In this world a somewhat common disability is losing your mana. There are people born without mana, but the first is more common. So it is essentially calling a story about a guy who gained asthma, the death of breathing. Melodramatic, yes, but it fits. Or it could be a smaller scope personal fantasy/drama focusing on how a person reacts to a wide scale disaster. The story focuses less on nations, heroes, and other grand things to instead focus on an average person trying to help their family and friends in this apocalypse. Or the first example I described but it isn’t the protagonist with mana asthma but a close friend, perhaps the person on the cover. Or the death of someone named Mana, and how it effects the people around them.
Although, I will say if this is a grand fantasy story than 1 fits better than 2, especially as Tsuru said with respect to the title.