When the Marvel TCG was first released, my friends and I picked it up as soon as we could and played quite a bit. With regards to both Limited and Constructed, we were quite pleased with the way that the game was designed. The games were fast-paced, but they still required a lot of strategy to play well. When we started playing the game, everyone in my group of veteran TCG players said "I think I just messed up" nearly every turn, which in my opinion is a sign that a game is made really well. In all honesty, I seriously doubt any of us are playing the game close to perfectly, in spite of all the hours that we've collectively devoted thus far.
There was one major problem with the game, though, as far as I was concerned, and that problem manifested itself in a variety of ways. In a fundamental sense, the problem was that a character's most important characteristic was its ATK/DEF compared to its cost. Special abilities paled in comparison to high ATK/DEF stats. Also, there seemed to be a pretty standard template for what the ATK/DEF to cost ratio of any character would be. If you look only at a character's ATK/DEF values and cover up the rest of the card, you can guess with 99 percent accuracy what the cost of that character is. The final manifestation of that core problem was that the set curve of characters' ATK/DEF stats to cost seemed fairly prohibitive in terms of future card design. Think of it this way: Is there a single character in the whole Marvel Origins set that you would even consider playing if it cost 1 more resource point, or is there a single character that wouldn't be terribly overpowered if it cost 1 resource point less?
The upcoming DC Origins set, much to my delight, has moved away from this sort of rigid cost/size curve to introduce characters with poor ATK/DEF to cost ratios that have exciting special abilities, and also the flip side of that, characters with awesome ATK/DEF to cost ratios that also have serious drawbacks. One of the most exciting cards of the former category is The Joker, Jokers Wild, which I predict will be a card that makes an impact in Constructed.
My first reaction when I saw The Joker was quite simply to laugh. I just imagined playing a 3 ATK/3 DEF character on my third turn and getting blown out of the game by my opponent's much larger, more straightforward play. While The Joker clearly doesn't shine if played on turn 3, the way it can affect both your opening hand and refuel your hand later on in the game makes it a very powerful card.
First of all, The Joker allows you to get rid of your opening hand if it contains The Joker, and redraw an opening hand with an extra card. This is a simple yet significant advantage—an extra card is worth enough that it's probably worth throwing away any opening hand that contains The Joker. Having an extra card in your hand makes your draw both more powerful and more consistent, and being able to start your first turn with an extra card at nearly no drawback makes The Joker a relevant card before the game even begins.
The fifth turn is where The Joker can really shine. An aggressive Constructed deck needs to play two different games. It needs to get off to a very fast start to overpower a slower deck, and it needs to make sure it has enough power to finish off a game that has gone on longer than would be hoped. It is often difficult to play both sides of this effectively. Most 0-cost equipment is excellent on the first or second turn of the game, allowing for increased early damage and favorable trades. However, as the game progresses, such a card is often not worth the card itself, as the bonus is simply too small relative to how large the characters get at that stage of the game. In the right deck, The Joker makes it possible for a deck to play both sides of this game very effectively.
Imagine a deck filled with lots of 0-cost equipment, quick aggressive characters, and combat-oriented plot twists. You can burn your plot twists and equipment forcing through early endurance loss and making favorable character exchanges, and when you are about to run out of gas, play The Joker to refill your hand. If you are able to empty your hand by the fifth turn, The Joker simply reads "Draw five cards," cards which will hopefully include more plot twists, efficient creatures, and cheap equipment. While playing a 3 ATK/3 DEF character on your fifth turn might seem a bit underwhelming, the fact that your board position should be favorable at this point (considering all the plot twists and equipment you have used to power through the early game), combined with the five additional cards you are drawing, should more than make up for his weak statistics.
Playing The Joker requires a very specialized deck (and that's without even factoring in the Loyalty drawback). To really maximize him, a deck will have to be able to consistently empty (or almost empty) its hand by the fifth turn. However, a deck capable of doing this will generate a huge advantage from all the extra cards. This, combined with the opportunity to mulligan into an extra card, makes The Joker excellent in spite of its very weak ATK/DEF. I personally expect The Joker to make a difference in the way aggressive decks are built, with a focus on overwhelming early in the game and refueling with The Joker on the fifth turn. Not only a very powerful card for Constructed play, The Joker also represents the Vs. game system incorporating characters with a wide range of ATK/DEF for costs with a variety of special abilities and drawbacks to compensate. I expect The Joker and cards like him to change the game significantly, and for the better.