Electivire Lvl. X is a very solid card. It isn't something that is going to be the cornerstone for a tier 1 deck or the type of thing you will build your strategy around, but can be a very nice compliment and be the difference in winning you some games.
The 120 HP, a +20 HP boost from the regular Electivire, is nice, but nothing too special. While it's body seems really great, the fact that you are going to be playing a max of 2 of these in a deck, and the rules in general that apply to getting a level X on the field that make it hard to swarm, makes it mediocre at best. With it most likely only being active for 2-3 turns as well, your opponent can play around it as well pretty easily.
Its attack can be very good when used properly. While Electivire's Giga Impact will be the attack you use mostly, you are going to be relying on his power Intense Voltage quite regularly to get it powered up quickly. Cessation Crystal, one of the top 3 trainer cards in the format right now, could otherwise cripple you without Pulse Barrier since Windstorms will not be as easy to draw into now. Not only do you get rid of all Cessation Crystals and other tools on the field along with their stadiums, it adds that nice effect of not being affected by your opponents attacks next turn (in most cases).
The weakness is a killer. Not only are you weak to fighting, which is becoming one of the strongest types in this format with Lucario, Rampardos and other fighting types running around, but it is double weak. This means that for simply 2 energy a Lucario does 80 damage to you, and a Rampardos has the ability to knock you out depending on your current HP. The resistance is pretty negligible, with Nidoqueen d being the only metal type I've seen used much so far in this format. A retreat of 3 is obviously very high, and with the number of energy Electivire's Giga Impact is already going to be discarding, makes it very tough to retreat this thing.
So what kind of combos can you use with Electivire Lvl X? Well, first you can give yourself a good draw engine by using Elekid and Electabuzz d to sit on your bench before evolving, and eventually leveling up. I personally think the new Raichu from Mysterious Treasures is a great play with this card. Many people have also been trying it out, with varied amounts of success, with Flygon d, which uses it's Delta Supply power to put lightning energy on Flygon itself, then use Intense Voltage to move it to Electivire. I personally think anything that is a great damage spreader, such as Prinplup or Empoleon, can help out as well by putting damage on the pokemon you believe they want energy on, thus using Shocking Tail to its fullest.
MODIFIED RATING: 6/10
120 HP is good solid, it's poke-body is solid, retreat cost and weakness kill it, but its attack, while situational, can be slightly above average, so I give it a slightly above average score. If Lucario and Rampardos weren't around, I would bump this up close to a 7.
UNLIMITED RATING: 1/10
While base set Electabuzz sees some play here, Electivire and Electivire Lvl X are terrible.
LIMITED RATING: N/A to 4/10
If you draft just Mysterious Treasures, it is a dead card. But if you draft something else that has it's pre-evolutions, this can be a decent card. 2 for 50 is wonderful in limited, but being a lvl X it functions like a stage 2, which are almost impossible to get out in limited.