Terraprisma design

Hi, I’m planning to make the terraprisma from Terraria but I’m not sure on how to replicate the glow effect evident on each of the flying swords. I was wondering how it would be possible to do so, preferably one that is not too consuming for the server. Would it be a glow effect, highlight or some sort? Thanks in advance, any help would be appreciated!

Maybe you can make a copy of the flying sword, then slowly increase the transparency and size

Thank you, but it does not lead to the intended effect.