A Public Service Announcements to Ubers Ladderers:
Stop using Thunderbolt on Mewtwo.
Thunderbolt does literally nothing for Mewtwo that one of its standard moves can't do better.
252 SpA LO Mewtwo Thunderbolt vs 248 HP Ho-Oh: 50.6% - 59.8%
252 SpA LO Mewtwo Psystrike vs 248 HP Ho-Oh: 63.6% - 75.2%
Ho-Oh is pretty much the only common Flying-type in Ubers that isn't weak to Ice Beam, so the only instances you would consider using an Electric-type move is against Water-types. And in that case you're probably going to have access to Drizzle (whether your own or your opponent's), so you can use Thunder. And even then Thunder isn't very useful. Example:
252 SpA +1 LO Mewtwo Thunder vs 248 HP Kyogre: 106.7% - 126.1%
252 SpA +1 LO Mewtwo Psystrike vs 248 HP Kyogre: 97.8% - 115.4%
You almost always pick up the OHKO with Psystrike anyways. Thunder is barely
defendable. Thunderbolt is not. Stop using it on Mewtwo. Stop using it on Genesect. Stop using it on pretty much anything except
- Electric Arceus
- SmashPass Recipient Dialga
OK Now that that's out of the way, LO CM is generally what I see the most of, and with good reason. It's pretty damn good at what it does and has quite a bit of power. The moves of the set are generally pretty easy to decide, something like:
Mewtwo @ Life Orb
Timid 252 SpA / 4 SpD / 252 Spe
- Ice Beam
- Fire Blast / Aura Sphere / Flamethrower
- Calm Mind
With Fire Blast being the especially preferred move in sun due to pseudo-STAB. Aura Sphere was perfectly defendable pre-Genesect, but given Sect's (and Ferrothorn's) prominence, Fire-type moves have become more important. By the way, never put the 4 excess EVs in Special Defense.
Genesect gets an Attack boost from Download if you do, allowing Scarf Genesect to smash you. No competent Genesect runs Bug Buzz on a Scarf set in Ubers. Don't be negligent about something that could turn out to be really important.