The only common thing that can OHKO Deoxys-D is Genesect, and even then it's only certain sets, and depends from where you put that 4 leftover EVs. Bug Buzz if you put on Defense, and U-Turn if you put on Special Defense. You shouldn't actually use Focus Sash, as apart from the attacks that I said, very few things can OHKO a full-health Deoxys-D. There are better items to use, such as Mental Herb, Rocky Helmet, Leftovers or even Life Orb. The only other "true" lead is Genesect, as a good (but not that good) speed and coverage means that it can actually beat a lot of common leads.