Dugtrio@Focus Sash
Arena Trap/Sand Veil/Sand Force
Jolly nature
252 Attack/252 Speed/4 HP
~Hone Claws
~Earthquake
~Stone Edge/Reversal/Shadow Claw/Sucker Punch
~Stone Edge/Reversal/Shadow Claw/Sucker Punch
Dugtrio's finally gained a means of significantly boosting its Attack stat that doesn't lock it into using only one move; Hone Claws. Earthquake goes without saying; nice, physical STAB, an obvious staple on any Dugtrio set. As for the other two moves... Stone Edge works well with Earthquake, as the two moves together provide nearly unresisted coverage (only resisted by Flygon, and even then, only because of Levitate). Not to mention, Stone Edge also benefits from Hone Claws's accuracy boost. Shadow Claw and Reversal, however, provide absolutely unresisted coverage. Also, what with the Focus Sash and Dugtrio's crappy defenses, Dugtrio is bound to be knocked down to 1 HP extremely quickly, making Reversal an extremely effective choice. Sucker Punch is also an option. It provides slightly less effective coverage alongside Reversal, but as this particular Dugtrio is toppled by priority moves, it only makes sense that Dugtrio should have a priority move of its own.
The item, Focus Sash, is there to ensure that Dugtrio gets a Hone Claws under its belt, as its defenses are laughable. As for the ability, any one of Dugtrio's abilities work here. Arena Trap allows Dugtrio to be switched in on, say, a choice'd Thunderbolt, and set up to its heart's content (hearts' contents?). As Dugtrio isn't designed to take a hit of any sort, however, caution is advised. Sand Veil allows Dugtrio a slight chance that it might be able to get in a second Hone Claws, or else evade a priority move that would otherwise end it. Sand Force powers up Earthquake and Stone Edge, but as it's not actually legal on Dugtrio yet, it shouldn't be much of a concern yet.