Thank you all for your replies!
I got it working most of the way. Unfortunately, when the unit spawns, it has the glow, but it's the wrong color (I'm using custom colors in my map; players 1 - 5 are blue and 6 - 10 are red).
I was hoping it would automatically change to be the player's correct color, but it seems like it needs a bit more elbow grease.
It did work correctly if I just had the unit in from the very beginning of the game, but that's unfortunately not how the map works.
Any advice would be greatly appreciated!
Oh, and I used the Sphere ability.
Edit: I had an idea. I could set the trigger to add ability 1 to players 1 - 5 and ability 2 to players 6 - 10. I would, however, need to know if there are separate models for each color, but that's something I can probably figure out on my own.
I'll report back if I get it working.
Edit: I got it working! I just needed to change the unit's color to their corresponding team's color as they spawned (the unit already appeared as the correct color but whatever - I'm happy

)