You can evolve more than one Pokemon during your turn as long as you have the correct cards to use and each one youre evolving has been in your Active Spot or on your Bench for at least one turn
Instead, the power decreases, so the combat power goes down slightly
And X=2 already gives you Ghostly Flicker or Displace efficiency
Since the RNG applies the negative effect to a random Joker, you want to ensure it goes to a decent one, not some random common Joker that does nothing and gives a minor effect to the playing cards
Incapsula incident ID: 537000110076815244-107022695196590834
One example given is the legendary angel Sigarda, Champion of Light, which not only buffs humans but also has a Coven ability that allows you to look at the top five cards of your deck and put a human from among them into your hand when it attacks