Sheele (Akame Ga Kill!) wielding Cutter of Creation: Extase, which is sharp enough to cut through any physical defense, even the impenetrable armor, Incursio.
Train Heartnet (Black Cat) firing an Orichalcum bullet out of Hades, which is capable of destroying any material on Earth.
Baraggan Louisenbairn's (Bleach) time acceleration powers can disintegrate anything from powerful Kido barriers to his own Resurrección enhanced Hierro.
Bambietta Basterbine (Bleach) transforms anything her The Explode power touches into bombs, bypassing any shields and physical defenses.
Moe Shishigawara (Bleach)
Lille Barro's (Bleach) The X-Axis does not use bullets, but simply pierces everything between the muzzle of his rifle and the target, with no barriers in between capable of blocking it.
Wei Zhijun (Darker than Black) can teleport using his blood as a catalyst, hence once his blood is on the target, there is no defense.
Nappa (Dragon Ball Z) using his Break Cannon, a powerful mouth energy beam that pierces through the foe's defenses.
Piccolo's (Dragon Ball Z) Special Beam Cannon, when charged enough, can pierce through enemy defenses and foes whose raw strength would ordinarily block Ki attacks...
...and pierces through Babidi's magical barrier.
Yajirobe's (Dragon Ball) Ka-Blam Slicer is a powerful sword beam that penetrates the opponent's defenses.
Laxus Dreyar (Fairy Tail) uses "Mercury Fulminate: Thunder God" to beat an electrically immune Wall Eehto.
Kenshiro (Fist of the North Star) using Hokuto Jūha Zan to harden Heart's skin, allowing him to bypass Heart's body fatty defenses.
Oboro (Gintama) using Hakkei to strike Gintoki's pressure points, causing a disruption of the meridian flow, thus cannot be blocked.
Utsuro (Gintama) using Hakkei to strike Kagura's pressure points, causing a disruption of the meridian flow, which leads to internal damage.
While Issei Hyoudou's (Highschool DxD) Dress Break is generally used for perverted reasons, it can also be used to destroy armor.
Inuyasha (InuYasha) using Meido Tessaiga to rip apart a Shikon no Tama protected Naraku.
The Shukaku's Pike/Spear of Shukaku (Naruto) is formed from the sharpest minerals compressed together and can pierce through even the Infinite Armor.
Particle Style/Dust Release techniques (Naruto) cannot be blocked since it will disintegrate any and all matter that it touches.
Using the hammer to add force to the ax, the Bluntsword/Blunt Blade the Helmet Splitter: Kabutowari (Naruto) can cut through all defenses.
The Third Raikage's (Naruto) Thrust of Hell: One Fingered Assault/Hell Stab: One Finger Nukite is his strongest spear, and can pierce through even his own superhuman body.
Using the Chidori, Sasuke Uchiha (Naruto) was able to pierce clean through Gaara's sand-based defenses and make him bleed…
…and firing chakra arrows through his Susanoo with such piercing force that no physical defense can block it, especially if he imbues it with the black flames that will incinerate anything they pierce…
…infusing lightning chakra into his blade to enhance it’s cutting power, allowing him to cut down armored samurai with ease.
Might Guy's (Naruto) Night Guy technique strikes at such intense power that it distorts the space of his immediate vicinity, bypassing defenses.
Kaguya Ōtsutsuki (Naruto) firing her "All-Killing Ash Bones" with such force that it pierced through Kakashi's "Susanoo".
Aruka Schild (Needless) using Agni Schiwattas to accelerate the kinetic movement of molecules, causing combustion that can bypass defense.
As a Rubber Human, Monkey D. Luffy (One Piece) was able to bypass Enel's electricity-based Logia defense and injure him…
…and later used his Gear Second’s Gum Gum/Gomu Gomu Jet Gatling to smash through Rob Lucci's Tekkai/Iron Body...
...and after two years of training, he can use Busoshoku/Armament Haki to break through the strongest of defenses, like the New Fishman Pirates' Steel Shell Formation.
Usopp (One Piece) using an Impact Dial to create a condensed shock wave that bypassed Monkey D. Luffy's rubbery body.
A Reject Dial (One Piece) possesses the same ability as the Impact Dial, but with 10 times the output that its defense-penetrating power can cause lethal damage, both ways.
Sanji's (One Piece) Diable Jambe can burn through any defenses, even the iron like defenses of a Tekkai/Iron Body master.
Rob Lucci (One Piece) using Ultimate Radius: Six King Gun/Sai Dai Rin: Rokuogan to produce a powerful shock wave that bypassed Monkey D. Luffy's rubber-based defenses.
Bartholomew Kuma (One Piece) using Pad Cannon/Pad Ho, piercing through every defense and obstacles with high-pressure air blasts.
Marshal D. Teach/Blackbeard (One Piece) can use his Dark-Dark Fruit/Yami Yami no Mi to nullify any Devil Fruit based defenses from Paramecia to Logia, making them more vulnerable to physical harm.
Edward Newgate/Whitebeard (One Piece) using Kabutowari to enhance his punch with vibrations, shattering defenses and causing tremendous damage.
As magma is superior to fire, Sakazuki/Akainu (One Piece) was able to bypass Ace's Logia defense and mortally wound him.
Batman's Shock Gloves (Batman: Arkham Origins) allow him to pierce through enemy shields and body armor, and cause damage to Venom users even while the drug is active.
Using the Beat Down, Batman (Batman: Arkham) unleashes a rapid flurry of punches to pierce through an enemy's defenses.
Using the Chaos Claws, Gabriel Belmont/Dracula (Castlevania: Lords of Shadow) can break enemy defenses using brute force and heat.
Using the Fury Dark Gift, Kain (Legacy of Kain) deals a single powerful strike that cannot be blocked.
When using Ripper Mode, Raiden's (Metal Gear) attacks are enhanced to the point that he can easily cut through enemy shields and body armor.
Metal Sonic's (Sonic the Hedgehog) V. Maximum Overdrive Attack can reportedly penetrate any substance. However, it shorts him out temporary after usage.
Zelda's (The Legend of Zelda) Light Arrow can pierce through all defense, causing normal targets to be vaporized in a flash of light.
The True Dragon Sword (Ninja Gaiden) forged from a dragon's fangs and empowered by a dragon's soul is immensely sharp, able to cut through armoured tanks and jets of steel and slice down the immortal bodies of Evil Deities such as Vigoor Emperor and Vazdah.
The Blade of the Archfiend (Ninja Gaiden) was forged from Vazdah's demonic magic infused meteorite, making it powerful enough to rip through the immortal body of the gigantic Goddess which has complete immunity to modern firearms and artillery.
When using the Superflame, Spyro (Spyro series) can pierce through the defenses of enemies immune to his normal Fire Breath.