I had originally animated a full loop for the glowing horn magic for >>1425395, before I erased most of it to only appear when necessary. (actually 2 loops, aligned A-A-B) 
I really liked how I did the the dust-like specks that appear and fade, though the outline animation was half-assed. When/if I animate horn magic like this again, I’ll likely do the outline after the particle effect so it has visible influence over the shape. Possible also making the particles all move in a consistent direction, like spiralling towards the tip.