This has been tested
Pokemon Name: Deoxys-s
Moveset Name: Anti-Lead
Move 1: Thunderbolt
Move 2: Ice Beam
Move 3: Shadow Ball
Move 4: Psychic
Item: Choice Scarf(wtf????!!!)
Nature(s): Modest(+SpA -Atk)
EVs: 252 HP/252 SpA/4 Def
Description: This set emerged from my hatred of the oh-so-common suicide leads(Aerodactyl, Azelf, other Deoxys-s, etc...). With Deoxys-s's excellent base 180 speed, a Choice Scarf set may seem unnessesary. However, Choice Scarf allows you to run a more offencive Deoxys-s EV spread while maintaining the speed to outrun other Deoxys-s(even if they are using max speed with a +speed nature), and every other OU pokemon, Scarfed or not.
You might be wondering why Psychic and Shadow Ball appear on the same set. The main reason is that Shadow Ball only deals around 80% to Gengar, while Psychic will OHKO them 100% of the time unless they are carrying a Focus Sash. Psychic also works wonders against Infernape and Roserade. Shadow Ball 2HKOs opposing Deoxys-s and Azelf, who doesn't have anything on you except for Explosion, which they probably won't use.
Thunderbolt is needed because of Gyarados, who will often think that you are using the Screen set and stay in against you. Thunderbolt is also helpful for revenge killing Suicune and other random water-types later in the game.
Ice Beam 2HKOs Aerodactyl, who doesn't threaten you in the least, as well as OHKOing Salamence, and 2HKOing Zapdos.
This set was primarily designed to utterly destroy lead Aerodactyl, Azelf, and Deoxys-s. None of these pokemon can OHKO you with a non-critical hit and most will predict a Taunt opt to attack. Therefore, the "suicide lead" will be unable to serve it's purpose of putting down rocks. While they could set up Steath Rocks on turn 1, they will be in a world of hurt, and should they choose to stay in, they would be down 1 pokemon and Deoxys-s would have full HP, ready to come back in later in the game to revenge kill or straight-up sweep.
Speaking of switching in, Deoxys-s can do this rather safely. 252 HP EVs allows you to survive an unboosted Outrage from Garchomp, most of the time, unless Steath Rocks are setup. You should have about a 50% chance of surviving in this case because of the RNG. Needless to say, that's pretty beastly.
Counters:
The main things that you have to worry about are Bronzong, Tyranitar, and to a lesser extent, Weavile. While you may think a fighting move such as Focus Blast would be useful for Tyranitar and Weavile leads, you can't OHKO Tyranitar with max HP, regardless of what you use. The best play is to just switch out against all of these, which you can usually do without concern. Choice Band Metagross can also come in on turn one to Pursuit you, but the strength of this set comes from it's unpredictibility so the odds of your opponent switching a counter just isn't likely.
In conclusion, Choice Scarf Deoxys-s makes for a very reliable lead and remains a vicious revenge killer for the entire game. It's high HP(304) and decent defenses make it easy for it to switch in safely at least once per game, assuming that you are at close-to-full-health prior to the switch.
This set also discourages the opponent's usage of Stealth Rock with their lead, as if they decide to set them up turn 1, then they will be at a great disadvantage.