If the creature that ends up as the target of the copy is that original creature with backup, it will get a +1/+1 counter, but it won't gain any abilities
Based on my own experience with opening this set, here's the pull rates for Mega Evolution: Double Rares (ex): 21.8% or 1 in 4.6 packs Ultra Rares: 10.9% or 1 in 9.2 packs Illustration Rares: 10.9% or 1 in 9.2 packs Special Illustration Rares and Holo Rares: At least 1 in over 55 packs With that being said, here's some of the best cards I've pulled from Mega Evolution and where you can get them right now: Should you get Pokmon TCG: Mega Evolution
However, once you get into the PSA 10 Gem Mints, you find the card's true value: Price Charting lists two recent sales of a PSA 10 Gem Mint 1st Edition Holographic Ampharos on eBay for $24,999.99 and $40,000
Remember that it's your last Special Summon for the turn
Lukka was the first compleated planeswalker to be revealed, getting offed pretty much as soon as the 'walkers arrived
The ease with which you can enable this makes it one of, if not the best alternate win condition in Commander
