I almost missed this post. I run a T-tar-Yanmega deck too, with 3-2-3 of T-tar, but only 3-3 of Yanmega. I liked the idea of this deck for the same reason you probably did: T-tar is a very powerful card but is an energy hog with no real way to accelerate attachment (other than double colorless energy), so you take advantage of the only Pokemon who can do decent damage for no energy and partially makes up for Tyranitar's weakness to fighting. However, my deck is a bit more of a dark toolbox variation because I run a 2-2 Zoroark line (take care of the legendaries and other high hitters) and a 1-1 of umbreon UD. I know people say that the latter is getting too old for the format with the new black and white Pokemon now out with 'unblockable' abilities, but I still think umbreon has a place in a toolbox deck. He can buy time to think or to get that extra turn you need to attach another energy to T-tar to one-shot a Magnezone prime or something. Also, the more and more black and white cards are released, the more likely it is that I'll catch someone offguard who isn't prepared for Umbreon. Dunno if that's completely logical, though.... I don't think Mandibuzz is a bad idea in a deck like this, though; both Yanmega and Mandibuzz can snipe, but while Yanmega is better at battling Donphan, Mandibuzz can hit Machamp or Magnezone for a whopping 100 (more with special dark) and Gengar for 200(not that Gengar should be of any concern to a T-tar user. On the issue of whether to use switch or not, I'm not sure what to say. I don't run it because with Yanmega having free retreat, it seems silly. Also, when I send Tyranitar up, I generally don't expect him to come back; he either wins the game for me or gets knocked out, in which case I send up Zoroark to finish off whatever Pokemon was strong enough to knock him out. However, there have been a few cases when I wished I could retreat him to the bench for free. Switch can also be useful for bringing your Cleffas back when they try to sleep through your turn (don't you love it that Tyranitar can power claw any baby Pokemon while it sleeps?).I would agree with shizuoiwaki about the dual balls; you don't need them with collector and they are flippy. The only trouble with Yanmega active while you build Tyranitar is that (as I bet you've noticed) sometimes (usually when you don't draw into a judge of Copycat) you find that you want to attach to Tyranitar or evolve Larvitar but can't afford to put down any cards if you already have the same number of cards in your hand as your opponent. Also, as I'm sure you know, you can't play any more cards down after Copycat/Judge has been played if you want to attack with Yanmega. Team Rocket's trickery is a possibility if you really need to play that energy/rare candy THIS TURN, since it will lower your opponent's hand and raise yours, allowing you to play more cards and still attack with Yanmega. I also REALLY like running an Unknown dark in my deck. That way, if you don't draw into any energies on a hand refresh, you can use collector to fish him out, play him down, and search for a special dark to attach to T-tar. Also, how useful have you found Cleffa? I'm genuinely curious, as I've taken my Cleffas out of my deck (they're on probation after sleeping through too many turns at Battle Roads) and want to know how they're doing in this kind of deck in the new format. I prefer to start Yanma turn one and then hit hard on turn two with Yanmega without risking any excess sleeping by Cleffa. I am also worried that, should I utilize Tyranitar's darkness howl attack, that I'll knock my benched Cleffa out for an unnecessary prize. Good luck with this deck and let me know how your playtesting goes. I play with my two brothers a lot (they run Steelix/Blissey and Blastgatr) but am not always able to go to league and so don't get to play my deck against a variety all the time.