Genesis Portal

A Genesis Portal is a doorway between dimensions created following the events of Sonic & Mega Man: Worlds Collide that serves to bring about the events of Worlds Unite.

History
The Genesis Portals were created when the multiverse collapsed following the improper reversal of the Super Genesis Wave. Their existence was eventually discovered by Silver the Hedgehog and Professor Von Schlemmer, and Silver set out to close the portals before they could bring further harm to time and space. One such portal released the Ifrit into Apotos, where Silver was forced to battle it alongside Sonic after it defeated a group of Dr. Eggman's Egg Swats. They managed to force it back through the portal and close it, but in the process Eggman became aware of the portals and began scheming as to how he could take advantage of them.

Metal Sonic later used such a portal in an effort to escape Sonic and other Freedom Fighters with a Chaos Emerald, and the two rivals ran up running into Silver in the Burning Ruin Zone. Both heroic Hedgehogs worked together to trap Metal Sonic on the other side of a portal that they then closed, with both later departing that zone using another two portals.