The portal flashes, flickering between a multitude of colours. Blue, green, yellow. Truly, an infinite number of realities were waiting to be explored. Though, a giant stick being flung through the portal interrupts your musings, followed by a bird the size of an ant, and dust being flung through. You needed to stabilise this, post haste.

You hold up your hands, purple arcane bolts flickering between them and the portal. Winds picking up and many more objects being ejected from the wild ball of untamed energy. 

"Come... on..." You groan as the purple arcane circles flicker to life and once again contribute to the spell. You narrowly dodge a rock and channel every ounce of mana you have and stabilise the wormhole. Finally, the flickering stops and settles. You can make out a solid reality behind the portal.

As you're observing, the portal changes. You watch as it shifts, changes size, and a figure emerges.