ThePonyTheorist ![Non-Fungible Trixie - Non-Fungible Trixie -](https://derpicdn.net/badges/2022/3/27/16483897828892240272071532.svg)
I’ll mention that the “glow” seen in the show is also seen on the outside when a horn is within an airtight container, so is either just stylistic or (if we wanna be fun) a separate charged particle in the air which is attracted to charged magic, or the ionic ‘outer surface’ of the horn perhaps becoming more ionic mid or pre spell.