If I understood that he wants it like DotA has it, to where it takes and makes a copy of the hero itself, not his target, then no, you cannot use an orb. A trigger that has a percent chance checking when he attacks and uses the spell string, or whatever it's called, on the item illusion spell should work. If you want multiple, you may need multiple dummies or something, unless you go around that by like setting castbacks and resetting cooldowns. Not sure if that would work even then.
(If I'm wrong, sry, but I haven't looked at a bunch of triggering stuff in WE lately)