Complete mission 3 and play it again. At the start, run past the statue and into the first hall. Kill enemies to collect experience points and orbs, then find the hallway with a wooden wall. Break through the wall and break the crystal to collect 1,000 orbs, then exit the mission. Repeat this to collect a lot of orbs.
Nero or Dante can perform a launch jump off of ledges that sends them flying far forward much farther than a normal jump. This is useful for collecting secrets or as a shortcut. To perform it, stand facing a nearby ledge that you can jump off from, then perform the Streak or Stinger attack (while locked up, press [Up] + [Attack]) and Nero or Dante will dash forward. The ledge cuts off the attack animation and will instead launch your character far forward.
To defeat Sanctus inside of Sparda in Mission 20, while Sanctus is airborne in his shield, get near and break it with sword attacks just like earlier in the game. However, he will sometimes block with the Sword of Sparda. When he does this, use the uppercut technique to break his guard. If you can, use the Devil Trigger while he is in the air to use a special combo and force him to the ground. If you fail to do the air combo, just let him fall to the ground. You may be able to get a few sword-based shots in, but do not try to rely on this as he may escape. At this point, use the uppercut in Devil Trigger form if possible. Afterward he will go back to being airborne again, in which case you should drop the Devil Trigger. After you have dropped his health down to about the 10% to 15% mark, he will use a charging sword attack (however, if you have perfected the aforementioned combo, you may bypass this). Defeating him requires precision. Time his charge towards you and uppercut to break his guard. Again, as soon as it is broken, get into the Devil Trigger uppercut and finish him off. During the second battle against Sanctus as the False Prophet, timing is once again vital. All you must do is uppercut his attacks away.
An easy way to drop Sanctus' Shield during either of his encounters, have a full Exceed gauge (Ex-act or Max-act helps), then approach Sanctus, jump, and perform an Ex Calibur. If the full combo hits, his shield will be down. You can now proceed to make him fully vulnerable to attack using the above method, or however desired.
When facing Dante in the Dante Must Die mode, it is easier to fight him if you jump in the air and use the buster to bring him up to you. Then, use the grab attack. Be careful; he might block and try to hit you.
Use Nero's Devil Bringer to defeat Demonic Bosses. Before you daze any demonic Boss, get your Devil Trigger as high as possible and activate it as soon as the enemy is dazed. Use the uppercut on the enemy. Using it in different areas of the enemy's body results in a nice combo.
Note: You must have a fully leveled up Royal Guard style and posses the ability called "Dreadnaught". Dreadnaught is performed by holding RB + Left Analog-stick Away + B. This ability encases you in invulnerable armor, depending on how full your royal gauge is. However, you can still perform Dreadnaught with an empty royal gauge and get about five seconds of invulnerability. You will also have limited movement during a Dreadnaught. Perform the Dreadnaught and, at the precise moment it runs out, switch your melee weapon (RT). If done fast enough, you will keep the Dreadnaught armor and be able to move freely. Note: You are still fully able to take damage, as well as move normally.
Lower the Blitz "electricity shield" quickly by use charged pistol shots with Devil Trigger activated. The most effective method is as followed: charge a shot, go into Devil Trigger, release a shot or more, turn off Devil trigger, and repeat. This will quickly give you Super Smokin Stylish before his shield has even dropped. This will work even with a level 1 Charge Shot, and is more effective at level 3. Once his shield his gone, use Devil Trigger again, then use the Devil Bringer to devastate him. Three throws should suffice to send him into "red mode". Once he goes red he will attempt to grab you and suicide himself to significantly drain your life and possibly kill you. Shoot normal shots at him to get more Smokin Stylish points at this point, and finish him off easily.
To defeat a Blitz as Dante, use Royal Guard style along with the Gilgamesh gauntlets. While the Blitz is in his yellow "electricity shielded" state, get near him and quickly press + repeatedly to perform a punch and cancel it with a Royal Block. Think of the move as the attack and try to constantly use + repeatedly. You will raise the letter grade of your style meter with each hit while quickly lowering the electric shielding. You are basically hitting the shield yourself, then blocking that hit so fast that you cannot see it happen. Again, just press + at the same time. This might be somewhat tricky at first, but eventually becomes easy. Once his shield is lowered, immediately switch to swordmaster style and use Real Impact uppercut with the Gilgamesh gauntlets at least twice. Throw in a Kick 13 if time permits and/or a Shocking. When he goes into his overdriven "Red Mode", immediately switch to Lucifer and perform Bondage. If done correctly, you should finish him off and get a huge stylish ranking out of one Blitz.
To get the stylish points for the Combat Adjudicator (machine that measures style) with Dante, use the Lucifer weapon and execute the Pin-Up repeatedly. Hold RB + Forward + Y Xbox 360 to execute the move.
Use the Pandora's PF398 Revenge technique to knock Sparda on his butt by . With Pandora equipped, hold X and make two complete circles with the Left Analog-stick and fire at Sparda. It may require two shots, but he will fall as if you used the stationary cannon.
To win the board game in the Game Room, keep in mind that the number showing on the die before it is rolled is the number that will show up if you count properly. For instance, if you would like to roll a "3", wait for "3" to show up on the top of the dice. Count six rotations before you strike the die and you will roll a "3".
If you use the Buster on the die (without locking target on the die), the number visible on top of the die before using Buster will always be set to the same number after punching the die into the air. Since you will only get the die rolling part with Nero, you do not have to worry about Dante.
When facing Echidna, turn on Devil Trigger and use Roulette Spin on her head. When she turns into a spider, power up and use Buster on her egg sack. When she grasps her forehead in pain, use Buster and tap [Exceed] to give the attack extra power.
Use Grim Grip to reel yourself near his head and attack with your sword. Once the combos are done, use Grim Grip while still in the air. When his flames are gone, jump up to his head and grab it with the Devil Bringer. Once he lands from that, use Devil Bringer again to throw and punch him. After that, run away a short distance to avoid his exposion attack. Make sure to roll to avoid his flame geysers and sword attack and pick up Green Orbs from the destroyed buildings and. Keep attacking in this manner and use your Charge Shot to defeat him in under a minute.
To collect 4,300 Red Orbs in about twenty seconds,destroy the rocks to the left of you at the start of the mission. Go into the tunnel and also destroy the rocks that are there to find the big red crystal near the Secret Mission. In order to get the most orbs, start with the Stinger and immediately go into Devil Trigger mode, then quickly mash away. Once done, press Start, go to "Systems", then "Retry Mission". This is the easiest way to get a lot of Red Orbs quickly.