The only exception is if the monarch and the knight are the last two players standing, in which case the knight may reveal themself and they both win
Excluding perhaps the Weezing-Koga deck (which had a brief moment in the sun early on), every deck that's at least moderately viable in competitive play has revolved around one thing: get a lot of energy onto a Pokmon, and then do a lot of damage with it
(2016-08-23) A conspiracy doesn't count as a card in your deck for purposes of meeting minimum deck size requirements
These are held at game stores across the world and are a huge part of the Magic community
However, while Mega Evolutions are incredibly strong Pokemon, losing them in a match is more punishing, as one down means applying the 3-prize rule instead of the usual 1 or 2
Usually, the abilities will be weaker than the standard effect for that price or more expensive than what the effect usually asks for, but thats the price of the versatility youre looking for