Despite not being great at DMC, I just got the platinum trophy, and I'd like to help others get it as well. It's tough, and at times very frustrating, but also very possible. I want to share many of the strategies that helped me through the tougher and more frustrating parts.
Some general information first:
You don't need S ranks with all characters on Missions 07 and 13. One character with an S rank is enough.
You'll need a lot of Red Orbs, millions, if you want to make it as easy as possible on yourself. Refer to this farming method: https://www.youtube.com/watch?v=iQ0usgbxoRc
Closing Application lets you start from the previous checkpoint without losing the No Continues (and No Damage, if you're going for it) bonus. Makes DMD S Ranks a lot less frustrating
Doing the above also means that anything you spent, such as red orbs with Dr Faust or devil breakers, is returned to how it was when you first reached the checkpoint
Hell and Hell is the same difficulty as Son of Sparda, and it has no checkpoints. This means that each mission must be done in a one go, start to finish.
Enemies that are off-screen won't attack you. Camera manipulation is key for avoiding damage. Do note that they will move towards you even when off-screen, and if even a small glimpse of them is shown for just a second, they might start their attack animation and actually hit you despite being off-screen. Enemies with projectiles are very scary for this reason.
For S Ranks: Human - 4000, Devil Hunter - 5000, Son of Sparda - 5500, Dante Must Die - 6000, Hell and Hell - 5500.
You don't have to defeat Urizen to get an S Rank. Dying to him still gets you the No Continues bonus, if you were eligible for it. Defeating him will guarantee it though. To speed up the fight, equip the Gerbera devil breaker and use it to counter his meteors. They'll hit his core/shield and do pretty decent damage.
Nero's Blue Rose(fully charged) and the Punch Line devil breaker means that most fights can be handled safely. If you're unsure of your abilities against certain enemies, just attack from a distance. The Gerbera devil breaker is great for dodging bosses, who without a doubt will be the most scary part of your Hell and Hell run. The Buster devil breaker can also speed up the boss fights since it does massive damage if you use its breakage power while in Devil Trigger. The boss must be vulnerable for the grab to work of course.
Mission 04 & 05
V is very tedious on both DMD and Hell and Hell. On DMD, the fights can take quite a while. Camera manipulation is again key, and the lightning strike(just holding his attack button) from Griffon is quite good. Getting S Ranks is not much of a problem, especially if you don't die and get the No Contnues bonus. You might not even need it, to be honest. The Mission 05 boss will take a long time to kill, it took me 13 minutes.
On HaH, both Griffon and Shadow die from one hit. This means that Nightmare should primarily be used for resurrecting them, and while Nightmare is out, they too become invincible. So go crazy. During boss fights, it's quite improtant that you keep them alive. Dodging to the side will make Shadow return to you, while dodging backwards or doing a double jump returns Griffon. You want them alive because dodging the bosses is otherwise difficult. The Mission 04 boss is a pain because of the lock-on system. You'll want to take out each of the heads in quick succession, but targeting the one you want isn't easy, and it might get you killed as you fiddle with it. Don't be greedy when finishing them off etiher, make sure it's safe or else you'll get hit.
Nothing noteworthy here. The boss fight is pretty tedious on DMD. Bring a Buster devil breaker, since he pretty much always falls down at a certain point, and is open for grabs.
Use V if you want a slow but safe S rank, or Nero if you want a quick but riskier S rank
A pain in the ass. You most likely won't be getting the No Damage bonus here, since you're meant to lose at the end. The way to get an S Rank is to get a lot of style points, but this is also a problem due to the enemies you face. The way I did it on SoS, HaH and DMD was to use the first three scythe enemies to get an S or SS. Use snatch and the ability to jump off enemies to build up style to at least C or B, before you start killing them. Air Taunts are great for building style without hurting enemies, and the risk isn't too high. Punch Line is great for keeping your style high. You generally want to avoid fights where you're not sure that you can get at least an S and maintain it. Don't fight everyone.
The Fury in the first mandatory fight can be easily dealt with using Ragtime and its breakage power. You'll need two on DMD. If you have Gerbera, you can skip the first pit if you want to. The second pit however, after the Divinity Statue, is really great for building up lots of style and I'd argue necessary for the S rank. You'll face many Empusas and one Behemoth. Use the snatch to keep yourself in the air, throw out Punch Line, use air taunts, and be aggressive in small spurts. When you get to Urizen, you have to beat the first phase. Once he's standing, you can just let him kill you. You'll still get the No Continues bonus.
A tedious V mission. The lack of a boss means that this is an easy one. Beware though on HaH, that when you first get indoors, you'll be faced with two of those large fire birds. They killed me a few times, so save up your devil trigger to deal with them quickly, and use camera manipulation.
Another pain in the ass, but the easiest way to get an S rank is to take no damage. You'll still need to build up some style points even with the bonuses, so take advantage of the easier fights such as the first one with the Empusas or the third fight with the Chaos (beware the spinning attack though). When it comes to Urizen, dodge his attacks and after a minute or so, attack the core with Ebony & Ivory (or any weapon of your choice) to trigger the cutscene and end the mission. If you're not good with Dante, like me, then use Dr Faust to deal with the tougher enemies. It uses up red orbs, but does a lot of damage. When in the Gunslinger style, you can send down meteors(Hold buttons for Lock-On+Forward on Stick+Style Power) that'll kill most enemies. Do this when they're spawning in, like the Fury in the fourth mandatory fight.
Again, use Dr Faust if you're not good with Dante. Even the boss can be dealt with using Dr Faust and some caution. You can spawn a turret(In Gunslinger it's Lock-On+Back on Stick+Style Power) that lets you shoot while also moving. This is great for pretty much all boss fights that Dante has. When the boss teleports away and charges his sword, do the same by charge the meteor stike with Faust.
You guessed it, another pain in the ass, mainly due to the Urizen fight at the end. You can speed this mission up a lot using a skip. This means that you'll only have two mandatory fights. One before the fountain, and one before the second blood clot..
As for the boss, make sure you have some normal Devil Trigger stored up for Royalguard. You'll start out in Sin DT. and If you're confident about dodging while in this form, attack him normally, but I'd suggest using the Shoot+Melee attack. It'll drain your Sin DT completely, but also heavily damages or even destroys his shield, and keeps you invulnerable during the animation. Once that's done, run away from him and use Royalguard to block the incoming tentacle attack, then start shooting with Faust, non-stop. He should stagger before hitting you with his next tentacle. He'll fall down on his kness, and you should just keep on shooting. He'll be at around half health by the time he stands up. Once he's standing, spawn the Faust turret. He'll have his shield back, so just keep running to the right (running left makes avoiding the laser and blocking his tentacle at the same time trickier), dodging his attacks while shooting with the turret. Whenever the tentacle comes, use Royalguard, since dodging them even with Trickster can be difficult. Stay focused, and you should be able to take him out without being hit at all, ensuring the S rank.
Pretty easy.mission. You don't even have to fight all the enemies, just destroy the blood clots. Do keep an eye on your style points, though I doubt you'll score so low that a x2.2 won't get you an S
By far V's hardest mission. Three boss fights, and as far as I could tell, no checkpoints between them. On HaH, you pretty much have to do it without taking any damage for the S rank. My route was to fight the middle boss(flying) with Griffon, then the right(Goliath) with Griffon and Shadow, and lastly the left(Knight) with the whole crew. Again, the lightning strike with Griffon is great, and on HaH, try to keep at least one of them alive at all times. If they die and you don't have Nightmare, remember to get close in order to speed up their recovery.
The journey to the boss can be a bit tricky. There's a Fury, but you don't have to fight it. As for the boss herself, use Gerbera to dodge and damage her with Blue Rose from a distance. When she goes berserk, be extremely careful while shooting her with charged shoots. Try to stay high up in the air. If you knock her down, then the Buster breakage while Devil Triggered is really great for damage.
Another tough Dante mission. Learn the enemy placements and use Faust if you want a quick and easy way to the boss. You do have to build some style though, even when going for the x2.2 multiplier. The final room before the boss with the Fury can be tricky, so I'd suggest building up Sin DT before getting there. Lots of white orbs on the way down. The boss himself is actually very easy with Faust.
When the boss fight starts, shoot him a little with Faust and dodge his attacks. Once the flames around his head are extinguished, start building up the Faust meteor strike, because he'll transition to his electricity form. Don't stop holding it down, as the boss and his projectiles are slow, and the meteor strike will eventually go off on its own and deal incredible damage, basically killing him. On DMD, he might survive, but he'll be knocked down, so just do another less powerful but faster meteor strike before he stands back up again.
Immediately start by charging your meteor strike up to two. Dodge his incoming attack, and shoot him with Faust. When he does a backflip, it means he's going to the next phase. You have enough time to fully build up a meteor strike and dodge his time bubble. Choose your time wisely to spawn the Faust turret, and much like Mission 14, just dodge while shooting. He'll eventually backflip again, and this time wait a second or two before starting to fully charge the meteor strike. On HaH, this will end the fight, but on DMD he'll still have some HP left. Once he's in Phase 3, he'll create two pink lasers and chase you, so you'll want to keep dodging, don't even bring up the turret. Remember to go right(counter-clockwise) to make dodging him and the lasers easier. Soon enough, he'll use the red spikes attack, and then do two melee attacks. After the second melee attack, shoot him with Faust from a distance. He'll eventually repeat the cycle with the pink lasers, so do the same as before. Here are two videos, one on HaH and the other on DMD:
You can deal with Griffon and Shadow just shooting them with Faust. If you need style, use the scythe dudes after Griffon and the Empusas after Shadow. In the final fight, beware Nightmare's laser attacks, and attack now and then if you dare. Once Nightmare is gone, use camera manipulation and shoot Griffon and Shadow while they're off-screen. Once they're down, Nightmare returns. He'll resurrect them, and while doing so, get to the side of him (if in front, he might use his laser attack) and use your meteor strike. At most, charge it twice. Holding it too long will let them scatter, and you might be attacked by Shadow. Then repeat the process if necessary.
If you're not good with Dante and Royalguard, like me, then rely on good old Faust for one last time. Early on in the fight, find the opportunity to spawn the turret, and the also use the ability to spawn red orbs that surround you (Lock-On+Shoot+Back on Stick). This will protect you from when Vergil spawns blue swords around you. Now you can just keep dodging him, and whenever he attacks and leaves himself open, just shoot him with the turret. Get in there and deal some damage too, especially early on before he DTs.
Here's a great video on how to make short work of Vergil
The Nero fight is even easier. Bring Punch Line and alternate it with Buster. You just need to know when to shoot and to use Punch Line, usually after Vergil finishes an attack. When Vergil is on his knees, use the Buster breakage in DT for a lot of damage. When the doppelganger shows up, use camera manipulation, and be extra careful about when to attack. If you're feel like you got the timing down, you can even Buster Vergil when he's doing the flying attack, as seen in the video
Please add any of your own tips, tricks and strategies that may help others.
Good luck everyone!