Some images are cute, but it's out-of-order-like that it's hard to like. Don't know if it's genuinely out of order, if there are flashbacks, if different "routes" are drawn and mixed in a confusing way, or another reason :/
to uareader the chapter (悪の胎動 D.Iris,Miina) in Ep.1 is a tipping point between (Ep.1~Ep.3) and (Ep.1~Ep.4). It's kind of hard to divide it to Ep.1 or Ep.4. I believe it's ok to leave it to Ep.1, because it tells the corruption of Iris and Miina then they turn to D.Iris and D.Miina. It might be good to make it connected to Ep.1. I must say it's much more confusing when first time to sort the serie (the artist even has a old serie which has the same character). For now in this story, Iris and Miina turn to D.Iris and D.Miina, then they start to "corrupt" their mates one by one (Yuuka & Ruri, Himeka & Konomi, Erin & Karen). BUT it's most confusing when Airi shown in Ep.4(Erin 覚醒) undercover to corrupt Erin, I don't even know where does she come from (last shown in Erin & Airi 1(https://www.pixiv.net/artworks/91348924), which seems like that Erin is already corrupted to D.Erin, god how confusing). I supposed Ep.1 is the real start of the new serie.