Welcome! A picture of the back would help as well in determining real vs fake.
But I don’t see anything wrong with it based on the two pictures above, so for now I’m saying real. 
You may have heard that a rainbowy holo is often an indication of a fake card, but it also hugely depends on the holofoil used in the card itself. Some holofoils are just more rainbowy in nature than others. I’ve just taken a look at my own copy, and in the right light, mine also has a faint rainbow glow. 
And the texts, font, positions of everything, and how large the black parts of the Energy symbols are (which are usually larger on fake cards) also seems to be correct when comparing.
Based on that slab, I assume you’ve picked this up during the 30th anniversary somewhere? If so, congrats on the addition.
Greetz,
Quuador