The user is able seal objects like living beings, spells, tools an,d/or weapons, etc. within another object or person and release them when needed. If the sealed object has a power of its own (Mythic Physiology, Powerful Objects, etc.) possessor may be able to tap into that power.
Master Emerald (Sonic the Hedgehog); only Tikal and Chaos
The Treasure (Homestuck)
Eshi (D.Gray-Man) forming chains out of dark matter, which is strong enough to seal away even Innocence abilities.
Dante Alighieri (Dante's Inferno) defeats Lucifer by resealing him in his bodily prison.
Mutaito (Dragon Ball) using the Evil Sealing Wave to seal King Piccolo into an electrical rice cooker at the cost of his own life.
Garlic Jr. (Dragon Ball) opens the Dead Zone, sealing anything that it sucks in, ironically his immortal self.
Mard Geer (Fairy Tail) used Alegria to imprison Fairy Tail inside Plutogrim.
Enraged after their fight ended as a stalemate, Halloween (Marchen Awakens Romance) decided to humiliate Alan by using his Darkness ÄRM, Igneal to seal him inside Edward the Dog.
Orochimaru (Naruto) using Five Pronged Seal/Five Elements Seal.
Hiruzen Sarutobi (Naruto) using Sealing Jutsu: Reaper Death Seal/Sealing Technique: Dead Demon Seal to seal his soul and that of Orochimaru's arms into the Shinigami's stomach.
Danzō Shimura (Naruto) using the Reverse Tetragram Sealing Jutsu/Reverse Four Symbols Sealing Technique to absorb everything into his own body and seal them away as his last resort.
Nagato/Pain (Naruto) using the Planetary Devastation/Chibaku Tensei, which seals the target into a pile of debris that forms into a celestial body.
The Jinchūriki (Naruto) are people who have tailed beasts sealed into them.
The Eight Sign Seal/Eight Trigrams Sealing Style (Naruto)...
...sealed Kurama, the Nine-Tailed Fox inside Naruto Uzumaki after his birth.
Obito Uchiha (Naruto) uses the Six Paths Ten-Tails Coffin Seal fuinjutsu to seal the Ten-Tails into himself, thus becoming the beast's jinchūriki.
Tenten (Naruto) seal weapons inside of her scrolls.
Gaara (Naruto) uses the Grand Sand Mausoleum Seal/Desert Layered Imperial Funeral Seal to seal his target in a great pyramid of sand reinforced with Sealing tags.
Shukaku (Naruto) uses the Grand Sand Mausoleum Seal/Desert Layered Imperial Funeral Seal powered by his Cursed Seals.
The Tekkofuin Steel Shell Seal (Naruto) sealed Gyūki the Eight-Tails inside Killer Bee/Bee.
Sasuke Uchiha (Naruto) uses Chibaku Tensei/Planetary Devastation to trap and seal all the Tailed Beasts.
Kumagawa's Book Maker (Medaka Box) has the special ability to seal away all kinds of abilities a person has.
Taoist (Valkyrie Crusade) sealed demons within her talismans, using them as weapons.
Bookend (Valkyrie Crusade) seals demons in a book she uses to banish demonkind, using their powers against themselves.
The Treasure (Homestuck) is a literal plot hole in the comic with the ability to seal others with Metatextual Attraction, overwriting their powers and imprisoning the victims in the harrowing nexus between canon, post-canon, non-canon, outside the canon, and fanon.