Illusion only work on other players and detects via proximity rather than targetting.
Stand on top of the person you want to turn into and enjoy two minutes of being a spellcasting bear (because let's face it, there's no point using it on anyone but a shapeshifted druid).
If there were any other minor glyphs worth having I wouldn't even have bothered putting this one in.
I, for one, have absolutely no doubt that Arcane, as an entire spec, in both PvE and PvP is going to end up in the toilet throughout the entire MoP expansion. You can bookmark this post, screenshot it if you wish, but you will see that that statement of mine will stand the test of time.
Blizzard might have fixed this, but it's fun to combine with rogues.
1. Get a rogue friend with their fancy new pickpocket glyph.
2. Send rogue friend to Zul Gurub.
3. Rogue friend pickpockets the Gurubashi Berserker style mobs. (Rogue friend ports to town if you want)
4. Stand under Rogue friend and cast Illusion.
5. Drink Darkmoon Firewater.
6. Cast Hero.
7. Pop Mirrors.
8. lol all over town.