Speaking of Geomancy Genesect, I've got a pretty simple set for it right here:
Genesect @ Power Herb
Ability: Download
EVs: 140 HP / 252 SAtk / 116 Spd
Modest Nature
- Flash Cannon
- Bug Buzz
- Geomancy
- Thunderbolt/Flamethrower/Hidden Power Ground/Ice Beam
The Speed EVs lets Genesect outspeed scarf lat@s after geomancy and ohko with bug buzz. Thunderbolt is the preferred option here after your two stabs for its ability to slam most pokemon, including skarmory, gyarados, and aegislash with a powerful neutral or SE move. Flamethrower can be used in its place to beat any steel type handily, and HP Groundis for heatran, who otherwise walls and ohkos every genesect set, ever. It also does some nice damage to aegislash. Finally, Ice Beam can be used to hit dragons, flying types, and ground types, but doesnt have much use otherwise thanks to the excellent power behind your STABs.