MS/EQ is great for soloing Gengar and may have other uses in the long run:
1. Super-effective against Steel-types, like Metagross.
2. Destroys pure Rock-types, like Regirock.
3. Only Ground-types are super-effective against Electric-types. If Raikou returns, you see an Ampharos in a gym or future generations introduce better Electric-types...
Groudon: Should I TM EQ to SB?
I caught my 4th Groudon today (I can hardly believe it), his stats are the best yet but he had FB. Used a CTM, got EQ. I don't have a lot of CTMs and don't want to risk getting FB again. What's your experience with EQ? My other ones have SB, but he's the one I'll power up with my limited rare candy.
Thanks for any input/opinions.

Answers
Some of these level 40 maxers grind a lot more stardust than me, I have a 3 y/o...even when I'm on holiday like I am this week I can't really pile it up. I try to get things to 30, then I try to get them closer to 35. However, I'm in a city, easier and better for me to be a more efficient raid organizer--I already know the gyms and the area well, gotta quickly get good players to the right gyms
Hold your horses! Don't use a Charge TM on this one until Groudon departs as a raid boss. You might catch an equally good one with Solar Beam. Also, Earthquake is pretty good. It has STAB and will be boosted by clear weather (as will Solar Beam). You should aim to have at least one good one with each of Solar Beam and Earthquake. Also, you should try to do a Groudon raid in clear weather so you can maybe catch a Level 25 Groudon.
I caught a perfect Groudon a few weeks ago and since I only planned to max 1 Groudon, I am still thinking about the best moveset. Different sites gave different opinions. I found 2 sites which one listed M/E as best attacking moveset while the other one listed DT/SB. So I am still wondering which movesets I should TM mine..
https://db.pokemongohub.net/pokemon/383
https://pokemon.gameinfo.io/en/pokemon/383-groudon
I honestly don't understand wanting to give Groudon Solar Beam. The game hasn't had a good Ground attacker since launch, and now that it finally does, we want to give it a Grass move? Yes, Earthquake isn't terrific, but it's still attached to some big stats with STAB. Let Groudon be Groudon: giving what is likely the best Ground type the game has two off-type moves just seems wrong, and chances are you already have some big Grass users with Solar Beam.