[Zekrom@Choice Band OR Life Orb, Lonely, Bolt Strike / Volt Switch / Outrage / Dragon Claw OR Focus Blast OR Draco Meteor+ Genesect@ Choice Scarf, Hasty, Ice Beam / U-turn / Iron Head / Explosion OR Flamethrower]
[Offensive / Strategics]
[CAN YOU SAY VOLT-TURN IN UBERS? This combo not only has excellent defensive-type synergy, but GREAT Offensive Synergy as well. Pokemon Genesect can't plow through like Giratina-a or Lugia are easily broken by the raw power of Choice Banded Bolt Strikes and Outrages. Genesect in return can easily beat up enemy Grass Arceus, Latios, and Latias, Pokemon that can annoy Zekrom with their high-speed or resistances. To add to the fun, both get STAB Volt Switch and U-turn, meaning that this core can easily keep momentum, preventing it from flowing out of a persons favor. This core practically defines hell for rain stall, and sand stall as well as classic stall aren't going to enjoy going against this core either. Pair this up with hazards and that residual damage rack will go up extremely fast.]
[Something notable is how this core cannot get past Groudon that easily, while it is 2HKOed by Choice Banded Outrage, and dislikes Life Orbed Draco Meteor, Groudon can threaten both Pokemon with Fire Punch and Earthquake. Ground Arceus can switch into everything but a +1 Ice Beam from Genesect and proceed to pound both Pokemon with a STAB Earthquake. Palkia is also a bit problematic, with access to Surf and Spacial Rend, Palkia can easily use its STAB moves to take down Genesect and Zekrom.]
[These simple problems can easily be assuaged with a Grass Arceus. Grass Arceus resists STAB Ground-type moves and can stop or even setup on a Palkia in the rain. Giratina-O can resist Ground-type moves and can serve as a spin blocker should you decide to use hazards to add to the damage their Volt Switches and U-turns do over time. While it doesn't help fix any problems permanently, Deoxys-S can provide hazard support, which when combined with the massive damage U-turn and Volt Switch will be accumulating, might just be enough to wear down the checks that can come in on the two, as their checks conveniently happen to be weak to Stealth Rocks and Spikes.]