Pokemon Total = 21
1 super rod
4 junk arm
4 sages training
Trainer/Supporter Total = 26
12 lighting energy
Energy Total = 13
Eelektrik lets you attach lightning energy from the discard pile to your bench pokemon, quickly powering up your pokemon. Magnezone is great draw card, allowing you to use judge and N without hurting yourself. It's an amazingly strong attacker, hitting for 50 per energy you decide to put in the lost zone. You want to be careful not to use all of the energy this way, so zekrom is a primary attacker to get as many KO's as possible before magnezone is needed. The new darmanitan is an awesome mewtwo counter, hitting for 50 times the number of heads on a coin flip, flipping a coin for each energy attached to darmanitan. Fliptini is to reflip darmanitan's attack if it doesnt go as planned.
I tend to play either a 3-1-2 or 4-2-3 magnezone line, depending on how much trainer lock is in the area. With cleffa in the deck to act as your free retreater, I dont know if there's a need for the 4th tynamo. If you're looking for room in the deck, that might be an easy one to drop. I really like thundurus in this deck as my starting pokemon, searching out energy from the deck and then feeding the discard pile for Eelektrik when it attacks.
With lost remover becoming more prevalent, if you want to use special energy, I'd recommend increasing it to at least 2.
I prefer N over judge in Magnezone decks, because it hurts your opponent more to draw into only 1-2 cards rather than 4. With Magnezone, you'll always be able to recover from a low N. Other than that, there's really no other suggestions I have for the deck. I would love to see more supporters in it, but there just isnt the room. If you decide to drop the tynamo though, that would give you room for an additional N. You could also consider dropping the fliptini and just taking your chances. To KO a Mewtwo, you'd only need two heads, which should be easy if you can get 4-5 energy on darmanitan.
You have an excellent version of Magnezone Eelektrik. If you can get a Mewtwo EX, that would be a better Mewtwo EX counter since it would be able to be set up in one turn and also give you more room in the deck. You should do very well in tournaments!