Some guildies of mine have been wondering why they occasionally see clone even when they are not mesmers.
So they went into empty pvp map to test.Certain mesmer projectiles have “Create a clone of yourself” as an on-hit effect. Namely, the third hit of the scepter’s auto-attack (and greatsword #2, but that can’t be reflected…)
If you reflect them and they hit something, then the projectile counts as yours, so it’ll make a clone of you to attack them. It’s similar to how reflecting a thief’s scorpion wire will pull them to you.
The amusing thing about this is, while mesmers are programmed to only allow 3 illusions at once, other classes are not. Theoretically, you could spawn enough clones to crash the server.