Alas, Poor Villain: Varael, Frunetti, and Satanael's deaths were given this treatment by Renya.
Ensemble Darkhorse: Liliel can be considered this, since she, just like Metallia, managed to rank in the top 50 fan-favourite (female) characters poll even though the game she's in hasn't even come out.
Amongst the angels, Kuroiel seems to be a fan favorite. The fact that she, alongside Liliel, is the only one who is legitimately nice to Renya helps.
Esoteric Happy Ending: While it's great that Cinderella and the Prince realize how important they are to each other and their readers, it still doesn't change the fact that she'll still constantly suffer at the hands of her step family every time the story begins.
Player Punch: In the final lesson, Mysiel shows the difference Renya made in guiding his believer's fates. Almost every single one of his believers are now living happier lives thanks to Renya's guidance. However, once the vision ends, the Fate Revolution Circuit deletes his memories of said believers...
Tainted by the Preview: Some fans think that the game's art style is too generic as was initial impressions of Renya when it was first announced.
Tear Jerker: Rakiel reacts to the death of Renya with his usual poise and stoicism. Or at least he tries...his voice quivers REALLY badly at one point as he's scolding Kuroiel. Especially poignant: basically, he and Kuroiel are the ONLY TWO ANGELS who actually give a damn that Renya is gone (Liliel notwithstanding).
Renya nearly losing his memories of Liliel. At first, Liliel's reaction is played a bit for laughs with her hitting Renya for forgetting about her, but when he recovers and remembers Liliel, Liliel utters the following:
Liliel: I had no idea...that it would hurt so very much to be forgotten...
The entirety of Lesson 6. The believer turns out to be Minamo in a future in which Renya is killed by Varael, leaving her all alone with absolutely no idea why her brother died since he never told her about her job as God. Considering what she had been through all this time, it's no wonder Renya chews out the angels for involving him in the war.
That One Boss: Chapter 4's boss level is agreed to be one of the most challenging in the main story. Your job is to protect a stationary NPC from hordes of aberrations climbing up to get you... all at once. The NPC is weaker, can only attack one space in front of him, and is extremely susceptible to even the weakest multi-range attacks. To make it worse, it's very easy to become paralyzed by aberrations, meaning you might not be able to move closer and save your NPC when he is in danger. Oh, and if you run out of health items? Beware to you.
All the characters keep talking about how powerful Satanael is and how Renya has to really be prepared to take him on, and they aren't kidding. First of all, the stage constantly spawns mooks and even when they aren't hitting hard, they're still annoying you with their numbers and long range attacks. Then there's Satanael himself who has a lot of range and damage on his Beam Spam attack and has a tendency to teleport when you get too close so it's hard to even get a hit on him. Finally, there's his Kamehame Hadokenattack. The attack is marked with yellow panels and activates in a set number of turns, but depending on where you are when the attack is set and the placement of the mooks, you might have no choice but to take the damage and when you do, it hurts (at least 1000-2000 damage)! The best way to deal with him is to pump up your defense, plan your moves, and hope you can outlast him.
That One Level: After the relatively easy first three chapters, Chapter 4 comes as an unpleasant surprise. Not only does its layout obscure you from knowing what you're (literally) jumping into, but the abundance of 'ABERRATIONS OUT THE WAZOO!!!' and rather sudden level spikes (as well as the introduction of new, more dangerous enemies instead of just battrio), Chapter 4 is the wake up call. Hopefully you'll have your fingers crossed.