Here's a anti-lead Mew set I've been using, but it also is an effective lure for Dark types that are x4 Fighting-weak (which in OU, is most of them). I have posted the set elsewhere so sorry for cross posting, a mod can feel free to edit it if they feel it's necessary.
Mew @ Colbur Berry
Ability: Synchronize
EVs: 248 HP / 32 Def / 116 SpA / 112 Spe
Modest / Rash Nature
- Defog
- Stealth Rock
- Superpower / Aura Sphere
- Ice Beam
I'll talk about the non-lure stuff first; I have a lot of pokemon on my team that are stealth rock weak and so I wanted a pokemon that could reliably Defog and couldn't be pursuit trapped. Mew, with it's vast coverage options and good bulk seemed to be that pokemon - as Reflect Type Latias and the like don't really offer good options to check their common switch-ins like this Mew set does. Initially I was running Iron Head over Ice Beam to set rocks in the face of Mega Diancie, but Ice Beam is above and away the better coverage option and dealt with the vastly more common Tank Chomp who was causing me more trouble. Speaking of which, EVs are for out-speeding and OHKOing Tank Chomp as well as Defensive Lando. Iron Head, and more attack EVs, can be run as an extra option if you also have a problem with Diancie.
This set is best coupled with a primary stealth rocker (I use Azelf) who can set rocks in situations where Mew can't (e.g. using Skill Swap against Mega Sableye) as that can take the heat off him somewhat and allow you to lure more effectively later. On the whole people have an awareness of Mew's sweet coverage and so if you use him as a lead they can get a little jumpy on a match-up which is too good to be true.
While Modest seems like a bit of weird nature given Superpower, I didn't want to compromise of SpDef - but by all means Rash can be run instead, I just prefer the SpDef as a slight option against the likes of Thundurus. Further, even with the Modest nature, you get an OHKO on Weavile and Bisharp and the 2HKO on Banded and support TTar - as you outspeed that was fine by me and putting a heavy dent into Scarf Tar was good enough. However, Rash 136 HP or Def and 144 Atk will get the OHKO on Scarf/Band TTar without rocks - and puts in much more work against Chansey and Heatran (though the bulk by comparison sucks). Superpower > Aura Sphere for TTar with its SpDef boost in sand, however Aura Sphere is a decent option if you're not much worried about TTar.
Mew naturally has more to offer in the form of Synchronize, which is great utility again status inflicters. The main trouble with this set is Ice/Fighting coverage isn't that amazing, and you do have a little bit of setup baitiness about you - but so long as you're cool with these limitations it it isn't much of an issue. Like I said, this set is extremely capable at getting its Defog in.
Replays:
http://replay.pokemonshowdown.com/ou-378732444 - Low ladder, but I still don't think the opponent's team is ridiculous or they played badly. I misjudged Lando as Scarf on seeing Ferrothorn, however Mew comes in and faints Defensive Lando then lures Bisharp like a boss. This is obviously a fairly idealised match featuring the set in action, but you get the idea.
http://replay.pokemonshowdown.com/ou-377593890 - Precisely the same situation as above, though this time after Lando and Bisharp I set rocks too. Also the ladder is slightly higher, but again not top tier.
http://replay.pokemonshowdown.com/ou-376581379 - What Mew can do if you run Iron Head instead, the guy is literally so incautious around Mew they don't even bother to use Protect on mega evolution turn of Diancie. Oh dear oh dear.
EDIT:
http://replay.pokemonshowdown.com/ou-378856768 - My latest match against a Scarf TTar hoping to Pursuit Trap me. Pursuit is too weak to 2HKO with the Colbur Berry, even in spite of the Superpower Def drop from its first use. Currently going Win-Loss 22-4, to give you an idea of whether the team functions well - of which Mew is a fairly integral part.
EDIT 2:
http://replay.pokemonshowdown.com/ou-379697904 - A match where I lure and ladder to 1600+, just to show it working a little higher up.
