So, now that Mewnium Z is released, is there any set that Mew could use it? I know that losing Leftovers is not something Mew would want, but summoning Psychic Terrain is a damn good effect, giving him immunity to priority and free Specs for Psychic, along with giving a nuke, making it have a nice offensive pressure.
You could try
Mew @ Mewnium Z
Ability: Synchronize
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Nasty Plot
- Psychic
- Aura Sphere / Dazzling Gleam
- Dark Pulse
Nasty Plot boosts your Special Attack to good levels. Psychic is the STAB move and triggers Genesis Supernova. Aura Sphere hits the Dark and Steel-types that resist Psychic. Dark Pulse hits opposing Dark types. Really though, after Psychic you could run just about anything depending on what you want to hit. Some calcs to show what it can do at +2:
+2 252 SpA Mew Genesis Supernova vs. 252 HP / 4 SpD Florges: 345-406 (95.8 - 112.7%) -- 75% chance to OHKO
+2 252 SpA Mew Genesis Supernova vs. 252 HP / 4 SpD Sylveon: 399-471 (101.2 - 119.5%) -- guaranteed OHKO
+2 252 SpA Mew Psychic in Psychic Terrain vs. 252 HP / 4 SpD Blissey: 283-334 (39.6 - 46.7%) -- 96.1% chance to 2HKO after Stealth Rock, 1 layer of Spikes, and Leftovers recovery
+2 252 SpA Mew Dazzling Gleam vs. 240 HP / 216+ SpD Mandibuzz: 224-264 (53.2 - 62.7%) -- guaranteed 2HKO
+2 252 SpA Mew Aura Sphere vs. 252 HP / 252+ SpD Umbreon: 174-206 (44.1 - 52.2%) -- 74.2% chance to 2HKO after Stealth Rock
+2 252 SpA Mew Genesis Supernova vs. 252 HP / 112 SpD Hippowdon: 570-672 (135.7 - 160%) -- guaranteed OHKO
+2 252 SpA Mew Genesis Supernova vs. 0 HP / 0 SpD Latios: 232-273 (77.5 - 91.3%) -- 31.3% chance to OHKO after Stealth Rock