This is the new mechanic introduced in X and Y. Basically, these are evolved forms of EXes. You get over 200 HP and some very strong (but expensive) attacks, but in order to evolve, you give up a turn. And yes, you still give up 2 prizes if they're knocked out.
Here are the two big ones, Mega Venusaur EX and Mega Blastoise EX. (http://pokebeach.com/2013/11/english-xy-cards-revealed)
Here are the EX basics they evolve from (http://pokebeach.com/2013/10/xy-tcg-set-mega-evolutions)
My thoughts: I see a lot of potential, but I’m not sure if they will break the game or anything. The problem is that they don’t have the speed that we’re all used to. Mewtwo EX is broken because you can just plop it down, attach a DCE, and do substantial damage out of nowhere. These things not only require a lot of energy, but have the HUGE downside of losing a turn when evolving. That one turn could be what an opponent needs to launch a counter attack.
As for the cards themselves
Mega Blastoise EX: The easier one to use thanks to typing. As long as you have deluge Blastoise, you can get this powered up no problem. What you get is a 220HP monster with an improved night spear. That’s essentially 180 damage for 3 energy. Even if they block the bench damage with Mr Mime, 120 for 3 is not bad in it’s own right. It’s basic, Blastoise EX, is not that strong compared to other Exes (I’m looking at you Keldeo), but I wouldn’t call it a bad card either. It could certainly hold it’s own (which is more than I can say for non EX evolving basics).
Mega Venusaur EX: This one seems a lot harder to set up. The attack is more expensive at four energy and grass lack the easy energy acceleration that water gets with Blastoise. BUT, I think crisis vine could prove to be worth setting up. If you have virbank in play, you’re doing 120 + 30 + 30 going into your turn. If your opponent doesn’t have any switching or healing cards, they will never be able to attack you. And like Blastoise, the basic of this one is pretty strong in it’s own right (it could tank with Virizion EX).
TLDR: I think they are good, strong cards, but the drawbacks will keep them from being gamebreaking (like Yveltal EX).
Here are the two big ones, Mega Venusaur EX and Mega Blastoise EX. (http://pokebeach.com/2013/11/english-xy-cards-revealed)
Here are the EX basics they evolve from (http://pokebeach.com/2013/10/xy-tcg-set-mega-evolutions)
My thoughts: I see a lot of potential, but I’m not sure if they will break the game or anything. The problem is that they don’t have the speed that we’re all used to. Mewtwo EX is broken because you can just plop it down, attach a DCE, and do substantial damage out of nowhere. These things not only require a lot of energy, but have the HUGE downside of losing a turn when evolving. That one turn could be what an opponent needs to launch a counter attack.
As for the cards themselves
Mega Blastoise EX: The easier one to use thanks to typing. As long as you have deluge Blastoise, you can get this powered up no problem. What you get is a 220HP monster with an improved night spear. That’s essentially 180 damage for 3 energy. Even if they block the bench damage with Mr Mime, 120 for 3 is not bad in it’s own right. It’s basic, Blastoise EX, is not that strong compared to other Exes (I’m looking at you Keldeo), but I wouldn’t call it a bad card either. It could certainly hold it’s own (which is more than I can say for non EX evolving basics).
Mega Venusaur EX: This one seems a lot harder to set up. The attack is more expensive at four energy and grass lack the easy energy acceleration that water gets with Blastoise. BUT, I think crisis vine could prove to be worth setting up. If you have virbank in play, you’re doing 120 + 30 + 30 going into your turn. If your opponent doesn’t have any switching or healing cards, they will never be able to attack you. And like Blastoise, the basic of this one is pretty strong in it’s own right (it could tank with Virizion EX).
TLDR: I think they are good, strong cards, but the drawbacks will keep them from being gamebreaking (like Yveltal EX).