80 HP / 125 Atk / 75 Def / 40 SpA / 95 SpD / 85 Spe
Heracross lives right down in the UU tier, but has also got a firm niche in the Ubers tier as well, as it is one of the very few Darkrai counters in the tier. Heracross's base attack stat is good in the ubers tier and can work quite well when KO'ing pokemon. Bug and fighting is weak to flying, psychic and fire, the latter of which is the only one commonly seen. But thats why there are 6 slots in a party right? His typing is also and excellent offensive one as his STABs cover many pokemon in the ubers tier for neutral damage bar Ho-Oh, Giratina, Rayquaza and Thundurus.
However, there are some downsides to Heracross. His mediocre defenses, hp and speed make him very vulnerable to faster ubers, like scarfed kyogre or arceus, as they can outspeed and can fairly easily 1HKO Heracross with a powerful move. However, this does not mean Heracross is a bad pokemon, it has a great niche as a Darkrai counter and if you know how to use Heracross, he will be a great addition to any team.
Without further ado, some sets!
I Kill You Darkrai! (Revenge Killer/Darkrai counter)
Heracross @ Choice Scarf
Trait: Moxie
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature (+Atk, -SpAtk)
-Close Combat
-Megahorn
-Stone Edge/Night Slash
-Sleep Talk
This set makes Heracross single-handedly the best Darkrai counter in the ubers tier. The aim is, start off with Heracross and if they lead off with Darkrai, hit them hard with CC or Megahorn. If not, then come in on the Dark Void from Darkrai and sleep talk for a 66% chance to OHKO Darkrai (bar sashed ones). SE and NS are for coverage, depending on who you want to hit, SE for Thundurus, Rayquaza and Ho-Oh or NS for Giratina and Arceus-Ghost. Sleep Talk is the main idea of the set, this adds unpredictability and can potentially net a KO on a Darkrai trying to set up. Moxie is there to increase the power of each attack you make every time you KO a pokemon.
This is the only set I've come up with for ubers. Anymore sets would be great and if you could test them that would be better. Thanks.