Portal -as its name states- is used for teleportation. User creates portal in air, which he can use to travel around places. Unlike other teleportation spells, Portal can also be used in offensive and defensive, to use to attack target and reflect their attacks back through portal.
Pathway : Simple technique, where user opens two portals at once, and moves between them by passing them. Nine Circles have rune stones which can open portal to their base for moment, expect Ashlyn.
Dimensia Blade : By closing portal when target is middle of it, user can sever almost anything. If you are strong enough you can resist portal closing and force it stay open for while.
Labyrinth Striker : User creates several portals and attacks opponent's in quick succession, making dodging attacks difficult.
Eternal Fall : By openning two portals, one up from target and one on their feet, user is able to make Bottomless Pit. Depending users will, he or she can either wait target reduce to ashes by air friction, or cut fall in middle to make them experience same if they would fall from 100 meters.
Ring of Ends : By forming large portal on air, Ashlyn can open pathway to even distant place. Then she tosses portal at targets, and those who are hit by it are teleported to location.