Portal Opening is a technique used by Janemba as a defensive and offensive technique, and also messing with realities. It also appears in Dragon Ball GT in order to open a portal between Earth and Hell.
In it's GT usages, the technique is used when two users create an interconnecting energy beam to each other, which creates a gate between their two different locations.
In the Dragon Ball Super manga, Fused Zamasu utilizes portals while in combat in order to utilize a variety of attacks.
Hell Fighter 17 and Android 17 use this in order to meet on Earth and merge into Super 17. Their portal also lets other villains escape from Hell. Piccolo and Dende use the technique to get Goku out of Hell to rescue his friends from the mighty Super 17. Piccolo states that this technique is a fusion of the mind between two Namekians. After Goku questions whether or not Piccolo can get him out of Hell, Piccolo contacts Dende at Kami's Lookout to create the interconnecting energy beam to each other, which creates a gate between Hell and Earth after several attempts.
- Dead Zone - A technique where Garlic or his son Garlic Jr. open a singularity to the Dead Zone.
- Illusion Smash - An attack where Janemba utilizes portals in order to fire punches at his opponent from a distance.
- Springing Forth from Another Space - One of Janemba's portal techniques where he creates a portal to absorb his opponents ki blast, and then opens the portal elsewhere to launch it at them.
- Vice Shout - A technique where the user yells out extremely loudly, cracking dimensional walls and creating a portal.
- The Power of the Dark - A technique where Evil Bardock opens a portal to the edge of time and space.
- Demigra's Wormhole - Specially timed magic based wormhole technique developed by Demigra that cause several time distortions following Demigra's defeat in the Crack of Time. Capable of infecting various people with Demigra's Dark Magic and transporting beings through time, to further Demigra's plans.
- Violent Fierce God Slicer (scythe) - Black's signature technique, upgraded and more powerful than before. It is powerful enough to cut dimensions, creating a rift in space-time. This rift spawned several clones of Black, all from seconds in the past. The rift can generate more duplicates if destroyed or the clones can regenerate on their own.
Appearances in games
In the story of Dragon Ball Z: Shin Budokai, Janemba's messing with reality creates holes in time and space that connect multiple dimensions and timelines together, which displaces people in time and allows the dead to reclaim their living bodies and return to the living realm.