User can open a hole in the universe connecting two non-adjacent locations. This may be done in a very neat manner, such as connecting two doorways in the universe, or it may be done very sloppily like breaking a rift in the space-time continuum. They may use Dimensional Manipulation to tear a tiny hole through two universes, use Spatial Manipulation to overlap two points in the universe or open a black hole or a wormhole connecting those two points.
This ability may come in the form of a "Portable Portal", which allows users to make instant holes in anything the circle can be stuck to. Offensively, the user can create vortexes to suck in objects.
Banishment by casting a portal at the target, sending it away.
Binding by opening a portal around a target, trapping it in between.
Deflection by opening portals to redirect attacks back at the opponents.
As the human form of the Key, Dawn Summers (Buffy the Vampire Slayer) can open portals to other dimensions.
As a Archai, Tyler Michaels (Charmed Comics) has the ability to create portals to other worlds, dimensions or planes by burning holes in reality.
Dan Phantom (Danny Phantom) forming a Ghost Portal.
Wulf (Danny Phantom) using his claws to tear open a portal between the Ghost Realm and the Living Realm.
Raven (DC Comics/Teen Titans)
While using his powers as Dr. Fate, Khalid (DC Comics) can open portals between dimensions by invoking the power of Min, the God of Travelers.
Breach (Generator Rex) opening inter-dimensional portals with her arms.
Doctor Starline (IDW's Sonic the Hedgehog) can use his Warp Topaz to bend space to create portals.
Eden Fesi A.K.A. Manifold (Marvel Comics) possesses the mutant ability to mold reality, to tear open space and time connecting one place to another thus allowing him to teleport to just about anywhere in the universe.
Portal Gun (Rick and Morty) can create portal to different universes, dimensions and realities.
Dimensional Scissors (Star vs. the Forces of Evil) open dimensional portals.
Fattah the Opener (The 99) can create portals that allow him to journey instantly to any location.
Star Swirl the Bearded (My Little Pony series) uses dimensional magic to open a portal between Equestria and the Human realm.
Yugo (Wakfu) is a skilled portal maker and can make portals to overcome obstacles and enemies.
Will Vandom (W.I.T.C.H.) opening and closing portals.
The Golden Tiger Claws (Xiaolin Showdown) being used to tear open wormholes.
Yin & Yang Yoyos (Xiaolin Showdown) can create a portal that leaves to the Yin Yang World.
Garokk (Marvel Comics) The Petrified Man
The Spot (Marvel Comics) easily creating portals while murdering Russian mob goons.
Lion (Steven Universe) can create portals by roaring.
Leonardo (Rise of the Teenage Mutant Ninja Turtles) using his mystical odachi to create a portal to escape harm from Meat Sweats.