Bref: lotsa hair, lotsa weird jewelry, lotsa randomly appearing and disappearing body markings, utter inability over here to tell who is who. (AKA Rust Metal Wasteland Syndrome.) I have a sneaking suspicion that people who grew up learning kanji are better at noticing and keeping track of small details. I also know that I'm worse than most westerners at it. (I misread kanji a lot too.) But still, it's one problem I often have with manga. There are two blond characters with exactly similar faces but one has completely *straight* bangs and the other has a slight *flip* to his straight bangs. This is enough for the Japanese to keep them irrevocably apart. It doesn't work for me. Gets worse when we have a black-haired character who looks exactly the same as the blond character. Easy enough until in one panel the mangaka doesn't ink in the black character's hair, making him look like the blond character. Then utter confusion sets in.
Of course the story here is a mess too. No idea who's doing what why and how come there are two angels when there used to be one and where did Imagine come from and... blah blah blah. But it doesn't matter. All that matters- besides the aesthetic pleasure of seeing men with hair past their bums kissing, which is not a minor point at all- is that our young human innocent eventually falls in love with the semi-demon Imagine and at the end leaves his new bride to go join him (new bride doesn't mind being literally left at the reception because she Always Knew It Would Happen. And has hero's best friend to go screw that night.) The relationship is the whole story: plot, motivation, politics, and cosmology (the end of the world is imminent, we're told) are the ignorable window dressing backgrounding it. Kind of like the production values of Blake's 7-- only people who don't get the point of the fandom think them worth mentioning, let alone complaining about.
Also kind of like Blake's 7 slash, and others of that period. The relationship is what matters. Nothing else needs to be taken seriously, or even mentioned in fact. Imagine is the frothiest of BL froth and B7 slash some of the heaviest fanprose around, but they're oddly sisters under the skin.