I can with the rinnegan. [His head turns to look at Guren, and the wind pulls the dark hair away from his face for once. His left eye is perpetually in a state of strange purple stretching from corner to corner, broken up by several swirling lines.] It's an eye technique which allows me access to the Six Paths.

[This makes no sense to Guren maybe, but it's okay.]

The portals don't lead anywhere but back to this place. They're unstable when passing through and give illusions after using them.