Since Rage isnt explained i would assume that it could be the same Rage as from "Hex: Shards of Fate" which is basically a Mtg-Clone (mixed with hearthstone) So that would mean that each time this creature attacks, its Power would go up by 4. But in this guess are a lot of assumptions involved. It could be simply a coincidence.
The way this is formatted makes Illusory a keyword (it's also incorrectly formatted in a more general sense). Every instance of Illusory on every card it's on will be "[Cost], Reveal [Card Name] from your hand: You may create a Legendary 1/1 White, Black, and Green Spirit Wizard creature token named Semiz Khul's Herald." That very much seems like not what you're trying to accomplish.
You need to make Illusory an ability word. Something more along the lines of "Illusory - [Cost], Reveal [Card Name] from your hand: [Stuff and things]." I would strongly recommend against that, however, because then you just have Forecast.
Also, legendary, white, black, green, and deathtouch shouldn't be capitalized in the rules text (outside of normal English rules, of course).
Also, this card is a little overpowered just because blinking and multiple tokens with deathtouch.
Also, why is it an activated ability that only does one thing and that one thing has a "may" clause in it? Why activate the ability in the first place if you wouldn't do it?