Please let us have the second-place round soon. I want Sand Rush Cacturne asap! lol Anyways...
Unaware Umbreon: I kind of like this one. Umbreon's track record isn't very good these days, with its support set being way too outclassed and its Curse set being garbage, but Unaware just might save it. Thanks to Unaware, Swords/Dragon Dance sweepers must tread carefully, as not only will their attacks not be powered up, but Foul Play will easily force them out if not KO them, so Talonflame, Excadrill, Garchomp, Diggersby, Mega Pinsir, Mega Scizor, Mega Charizard X, and regular Gyarados will be forced to switch out and lose their boosts, thus making Umbreon a great emergency stop to them. Special setup sweepers like Manaphy, Latios, Mega Slowbro, and Raikou are also unable to break through Umbreon's defenses, which is a nice bonus. Curse sets would be pretty nasty to face when you can't setup alongside it, as once Curse could mean the end for your physical sweepers, as even Kyurem-B can't break through Umbreon's defenses without Outrage. I gotta say, I'm liking this more than I thought I would.
Sucker Punch Pangoro: I can see some usefulness in this one. Pangoro already has just enough to pull its weight in OU, such as Gunk Shot to hit Fairies, Fire Punch to hit Ferrothron and Mega Scizor, and Parting Shot to cripple switch-ins and gain momentum. But Pangoro's biggest issue was always its horrendous Speed, leaving it at the mercy of so many threats that are so much faster. However, Sucker Punch will at least give Pangoro a chance to get the jump on sweepers that get greedy and think they can get a kill. As mentioned before me, Bisharp would appreciate a Sucker Punch teammate that not only threatens Steel-types with moves like Hammer Arm and Fire Punch, but also provides it a free switch thanks to Parting Shot, much like how Pangoro appreciates how Bisharp can handle Clefable and Sylveon very well, so Pangoro would be pretty effective with Bisharp as an offensive core. I like this one, but why doesn't Iron Fist power up Sucker Punch? Why, Game Freak? :'(
Mold Breaker Shuckle: I'm not getting this one at all. I get that the point of this is to let Shuckle get past Magic Bouncers and have unblockable Sticky Web and Stealth Rock, but that really isn't much of an improvement and doesn't fix any of its bigger problems. Shuckle is still beyond passive, vulnerable to Taunt, has a mediocre defensive typing, and lacks recovery, and considering the fact that Mold Breaker will only help against 3 or 4 Pokemon in Shuckle's case, it basically has no ability most of the time. I get that being able to set up hazards without worrying about Magic Bouncers is cool and all, but we're talking 4 Pokemon that ever see usage in OU with Magic Bounce, so this newfound niche will rarely be seen. Sorry, but I'm not liking this one too much.
Speed Boost Mega Latios:
Yeah, we might have gotten carried away with this one, myself included. My reasoning for thinking this wouldn't be broken was that Latios doesn't have a means to get to +2 Special Attack, which is what got Mega Blaziken its banishment. As it would turn out, many of you think that this is broken, and I'm starting to agree. With solid 80 / 100 / 120 defenses and a decent defensive typing, Mega Latios can easily take a hit if need be, and Calm Mind would make special attacks even less effective on him, and combined with 130 / 160 offenses on top of a wide movepool, trying to take a hit will be tough for offensive Pokemon. Having base 110 Speed before and after Mega Evolving is already great on its own, but adding Speed Boost to the mix would make it very hard to revenge kill this thing. In fact, Mega Latios' stats are so good that you don't even need Protect to safely set up, as he has the bulk to take a hit and the initial Speed to outrun key threats, so a Calm Mind + 3 Attack set would be very threatening. Long story short, I love this idea to death as Latios is my favorite Pokemon, but I still won't be voting for this.