Warp Portal is magic, since it uses a magic circle. It requires both starting point and destination to have such a magic circle, as well as a catalyst (a ring in Rimuru's case) to work. After Rimuru gained the Extra Skill Spatial Travel he no longer needed the catalyst for that and once memorizing the spatial coordinates (or the destination being in range of his Magic Sense) he can directly use Spatial Travel to get there instead, not needing Warp Portal for that anymore.
Sorry for the late reply, all admins have voted so welcome you are this wiki's first content moderator. So you must have the Layout Guide and standards of the wiki on your mind, also join the Discord so you can join the wiki mod chat
Hello Zero, Thank you for taking care of the wiki in my absence. I have not been very active on Fandom as of late, but I check on the wiki from time to time. I will like to ask that I noticed some duplicate images and some unused images, I was going to ask if you plan to make use of them or I should delete them.
Due to Spectra's absence and Bloodstain stepping down from adminship, I will like to make you an admin for the hard work and dedication you've put into this wiki.