This game is a flawed gem, I'd rate it 4.5/5 if I could, but since it made me cry during my first ending it's closer to 5. Just don't come into this if your expecting porn and want to be a good guy, 99% of the sex scenes in this game are rape, with several rape attempts done by others(Which can be thwarted) and a rape of a side character being all you're getting until you finished the game. This will mostly be a guide for people that are confused, I'll be giving out tips that the tutorial glosses over or doesn't tell you about until much later(or not at all). Just keep in mind I played this game as a good guy, I can't comment as someone who committed evil, you monster.
Overview
You basically play as a weak demon who has to use mind powers to get people to follow you around. You're not a nice person to begin with, you only see those around you as pawns. But you've also never experienced a life of happiness, you've only experienced a life of poverty. Suffering a curse that your brainwashing abilities gave you, you must slay the demon who gave you these powers in order to not die. Thankfully you found 4 sisters, one of the strongest parties around that will aid in your quest, unwillingly. Over time maybe you're feelings towards them, and theirs towards to you will change, or maybe you'll go over the line and become the demon that you appear as.
Basic Combat
Standard rpg/wolfmaker fare, so don't expect too much from it. You tell a character to attack they attack But before you can properly get into combat you'll notice how weak you, Julius are. Your stats suck, you really do need the sisters to help carry you through most of the game, and outside of certain fights you'll be controlling them. But at the same time, they don't trust you enough to listen to your orders at the start, expect Irito(best girl) who will always follow you, just level them up a few times and you'll be good. Your moves can only be used for so long until they become exhausted, which can only be replenished by leaving the dungeon or finding one time recover spot(they regenerate every dungeon run) on certain floors. Thankfully the more you used a move, the more times you can use it, until it gains a little * next to it's name which means it's at it's max level. Weapons and armor also have this feature, using them enough times in battle will improve their stats for that character, with certain weapons also having special skills tied to them which can be learned once the weapon has been used enough. You can only equip 4 skills at a time so be careful with your combo, you will always have at least an attack command, and a escape(defend during bosses) command. And if you somehow manage to use all of a character's moves, pressing shift will let you struggle, a piss poor attack that's better then nothing. Shift is also how you use special skills and field commands, which I'll get to later.
Advanced Combat
So you've gained a few levels, even a few skills, and you're gearing up for the boss and you've started to notice something strange, field effects. The tutorial for this happens quickly but it doesn't really matter at the start, and won't for a bit more but it's better to learn to abuse it as fast as possible. Basically field effects will empower certain aspects, such as fire spells or weaken your party during a battle. Learning when to use a fire spell when fire effect is up is easy, the important part is what comes next, field effect skills. By pressing shift you can tell your characters to provide a special skill unique to them that will alter a field effect. Either by erasing it, changing it, or flipping it, by using this feature when it benefits you the most will save you many hardships. But they can only be used once, so it's better to only use it when you have to, but they do replenish when you reach a recover point. Later on you'll learn special skills by equipping(or getting a passive much later on) a tome on a character, these are also character specific and can only be used once as well. Catastrophes start becoming a threat, it's a mechanic usually only prevalent during a boss fight that will make them do major damage if you don't stop them. Debuffs and attacks will break a catastrophe, whilst also providing a small buff to the party member who broke it. If you manage to not break it by that time you better be ready to defend, something exclusive to boss battles. You'll also notice an orb at the bottom right rising up, this is acclimation points, the higher it gets the better the rewards are. There are no downsides at all to having a high value, although you lose them all when you teleport so be careful with that. Get a large amount of it before you head back from the dungeon and you'll gain bonus items, and mana too. It also increases your mana pool back at home, which I'll get to later. Just be sure to remember, debuffs are the way to go, bosses are not meant to be headbutted until they die, weaken the shit out of them before you pummel them and you'll have a much better time.
The Inn
Home base, where you can talk to the sisters for some fluff and just listen to Irito's beautiful music box. Which by the way, touch it a bunch and you'll gain the ability to carry it with you to the dungeon, and if you've played bloodborne it'll have a special use later on so you'll want it before the midway point. By going to the door to your bedroom you can see any scenes you've seen and a few other options, touching the light at the table lets you vist stores and karma exclusive areas, and the book near that light will let you buy equipment and consumables. Finally the light near the entrance is where you'll use those mana orbs you bring back, allowing you to upgrade certain skills that you and the girls have, you can only carry a maximum of 5000, so be sure to use them. You can give orders to the sisters here, but you can do it anytime in the dungeon too, although there are special ones that can only be done at the inn. Check back at the inn every now and then and you'll get some special scenes.
Gathering/Synthesis
What you want the good stuff, info on orders and karma and- just suck it up. Gathering resources and crafting is the lifeblood of the game, it's where some of the strongest gear is at. Gathering is simple enough, approach a node and press interact(Z) to gather, but wait there's more. By pressing 1 near a node you can upgrade it, with just a little coin, to increase the amount you gather. It also has a nice side effect of making the nodes appear easier to find, helpful. But gathering also reduces Julius's health, further reinforcing his weak status. You can later find a passive that decreases the amount of health lost, but right now he shouldn't be on the frontlines. When night comes, enemies will attack more often, but the resources change to a special night type. You'll need plenty of both so don't be afraid to stay after dark. Now to craft, hit the synth butto- what you complaining because you knew that? Sure it may seem obvious but I bet you didn't know you save hitting archive, huh? Anyway crafting is pretty simple, but you also get a special resource during exploration called material magic. These can only be used at the inn, and you can only have 9 of them at the time, so use them when you can. They only offer the basic resources of the latest floor you've been to, so it's not too useful.
Exploration
You may notice that there are hostile enemies that attack you when you approach and friendly npcs that you can talk to. Those npcs barely provide anything useful, without mind powers that is. But that's coming later, just be sure to hit 1 whenever you find a new npc. That'll provide you with special information usually related to a dig spot or treasure info. Dig spots can be found without the help of a npc, but unless you're hitting interact everywhere... Treasure however is different, you want this for reasons I'll explain shortly. Explore until the minimap is full and you'll gain a bonus item or ability, so get exploring. You'll also run into areas covered in blood and bones, these areas are where you'll be getting your mana from, don't be afraid to explore them. You'll find altars and other interactables, remember save often if you're in doubt. Altars are only useful if you have treasure info, these allow you to get a special item by offering other items. But it's time for dungeon diving, you'll find whilst exploring a hole in a wall that leads to a menu, these are mini dungeons, and can't be found without treasure info. Most are just a mini boss fight, but some lead to whole new areas. Completion of these dungeons will grant you the coveted treasure, some gold, mana, a crystal, and... an outfit? You're not guaranteed an outfit, and they're randomly generated so be sure to do them all. There are also events with a !, *, and character icon. Interacting with ! will provide fluff, * is story progression(you'll get a warning when you get to a crucial part of it) and character icons are only useful when you get a passive skill later on. The character icons increase affection with the right response, but don't feel too pressured about that.
Orders
Keep it in your pants, literally. By using up mana you can order the sisters to do all sort of lewd things such as, hand holding! You can only give a sister 3 orders before the mana required to give one increases to the next tier, which is unlocked by progressing to the next themed area of the dungeon. Keep in mind that outfit change order only unlocks when you've got an outfit for a girl, so maybe keep an order handy for it. But be careful with you force them to do, molesting and rape leads to a path where you can never get their good ending, and plenty of bad karma too. Now orders can also be used on npcs too, 1 is of course the demand info key. 2 is stealing, which will give you bad karma if done too much. 3, requires the usage of a special gamebreaking item. 4 is the rape key, which can only be used on female npcs and will permanently tarnish your soul. 7 is the special key, it lets you do unique functions try them out, asking about an npc is quite useful. You must strive to res-STOP RAPING BEFORE I TELL YOU ABOUT KARMA YOU FUCK.
Karma
Yes you're a demon, yes you do bad things, yes you can rape best girl(you fucking monster) but that doesn't mean you should and won't be judged for your actions. By actively doing bad things you tarnish your soul, which allows you to go to certain areas that were refused to you before. But there is no good ending coming your way, the moment you molest or rape a girl, your committed to the act of tyranny, there is no coming back to the fate that awaits you. But minor crimes like stealing will be cleansed upon doing good things, like not stealing from a dead corpse, or helping people. You can ask an old man standing near some boxes on floor 3 what your karma level currently is, and if you've committed a grave sin. Do enough good and you'll be locked out of evil actions for the rest of the playthrough once you hit the halfway point of the game.
Affection
Short and sweet, affection isn't super important. By fighting a girl may get 1 point in affection at the end of a battle, and once it hits 10 they get a passive skill that can be equipped on the 4th skill slot. It only unlocks more character icon events, so exploring older areas can result in more character development. It doesn't really have any effect on the ending, although having it be too low may end poorly for you, but by the point you should have enough affection for it not to matter.
Endings
You spent 10 hours grinding to finally achieve the anime ending scene of your dreams, but before that is there new game+? Yes there is, you keep a decent amount of items and all your skills from the previous run. You also keep 1 key item, the one that lets you see hidden objects but it's gotten so early it really doesn't matter. Affection is reset but levels are not, not to mention you unlock BONUS events, and orders which I have yet to see. You can freely view any ending you've gotten at the title screen, so I hope you brought tissues. And finally for going into new game+ you can finally see Julius face, what a reward. Just be to sure to activate it at your bedroom later if you actually care. As for the good endings, it's entirely(probably) based on who you talk to before the final battle, so be sure you do Irito first, because god damn does she deserve it.
Final Thoughts
I certainly missed some things here and there, but I tried my best. This is a really good game, at least for someone that plays as good. But I doubt you'll be aroused whilst doing that. It's not something that needs porn actually, I would've been fine without it. I can only imagine the terrible events that occur if you play as an evil dude, at least you get a choice unlike in Venus Blood. Irito alone is worth it, but the rest of the cast can stand up just fine without her. If you're on the fence on whether to play this or not, give it 2 hours. If it doesn't hook you by then it probably won't. The Protagonist does get better though, with time he opens up and starts acting like a human, yet still very much like himself. Character development like that is rare, for that alone it's worth a play in my eyes. It's kinda funny how playing the game for it's porn ruins it, like a commentary on the meaningless of sex without working for it. But regardless of how much you wish to ruin the game, I hope you have a good time. Just remember when you go into hell for ruining Irito's dreams, I'll drag you down deeper with me.