Most gremlins live in the Universe now, but there are ways back. Twisty little paths, easy to miss, but some gremlins know them. Some even use them. You gain Interplanar Teleport as a primal innate spell. You can cast it twice per week. This can be used only to travel back and forth between the First World and the Universe. Due to your body's natural resonance, you can act as a locus for the spell, and you don't require a specially attuned planar key.