Broken Time Space - This card, like Rare Candy, also breaks the fundamental rules of evolution, allowing both players to bypass the 1-turn waiting period between each stage in a Pokemon's evolutionary cycle
For most decks, being restricted to only cards that cost three or more means that Keruga, the Macrosage has the same exact issue as Gyruda, Doom of Depths: you only get to play a single card over the first three turns of the game, leaving you in a position where you're often dead to aggressive decks (this gets even worse in older formats, which are faster and place a higher value on efficiency)
Its an uphill battle once your opponent has four 3/3 tokens
If luck isn't on your side, try saving up Pack Points and then spend them on the immersive card of your choice
The card shows actual birds flying around it, so we know that on the Celtic mythology inspired plane of Llorwyn, birds exist