Snorlax is clearly ridiculous in this game mode, but whether we ban it depends on what people want from this mode. If we are trying to have a metagame which is sort of balanced, then we should probably ban it and either ban or restrict explosion. However, the game mode is sort of a novelty in the first place, and it isn't totally unplayable in its current state. To avoid confusion about what is allowed, I am inclined to say we should just keep it the way it is and come up with strategies to fight Snorlax/Explosion with (which do exist).
Here are some observations I've made from the games I've managed to get so far:
- Many different variants of monolax are viable. Curse RestTalk is decent, and pretty much any combination of LK / Curse / Drum / Protect / STAB / Selfdestruct also works. There is pretty much no point in running anything other than STAB attacks.
- Both Zapdos and Raikou are still good. Reflect Raikou can be very annoying to deal with if your team is Explosion-based, and is also good for Ground-types in general. Zapdos can run RestTalk like it usually does, but it seems like sets like Reflect and Substitute definitely have their niches.
- Exploding Poison-types like Muk and Weezing seem to be pretty decent, not having weaknesses to either bolt/beam or normal attacks, and they have useful Ground and Psychic resistances. Poison STAB is also pretty strong. Weezing can also Haze against Protect Drumlax with some degree of safety.
- Articuno is a pretty decent pick for its ability to handle Electric-types along with decent typing. It is only weak to Bug, Grass, and Ground. Moltres seems like it would be good in theory as well, again thanks to Electric-resist, although it is obviously significantly less sturdy than Articuno.
- Gengar is very scary with its high speed, access to great coverage (Thunderbolt/Ice Beam/Giga Drain for boltbeam neutrality/resists) as well as Hypnosis/DBond and of course Explosion.
- Miltank is common and can potentially stop Curselax from getting out of control if it doesn't have or has already used Lovely Kiss and doesn't have Belly Drum. It can also run a Curse set itself pretty decently now.
- Umbreon has potential, although it is CurseDrumlax bait.
- Heracross and Marowak are both solid. Only Ttar resists Heracross's Megahorn+EQ, which Heracross has the option of running a Normal attack for. Marowak is stopped by nothing with EQ+Return.
- Baton Pass is obviously very scary, nothing really stops a fast Drumlax (other than faster exploders) or Marowak (with Protect or Substitute for Cloyster/Weezing/Muk Explosion). It's probably a good idea to have a Hazer/PHazer. Explosion might not cut it against Substitute Jolteon/Smeargle.
- Cloyster is good, but can struggle when a lot of Pokemon have Ice-type attacks, and Cloyster vs Cloyster is very risky speed tie. Forretress is okay since little can OHKO it and it can set up and remove Spikes and Explode.
- Exeggutor has a lot of potential since it can both status-spread and explode. Psychic+Grass is also a great combination, hitting many important Pokemon hard.
- I would not recommend using Steelix, Fighting-types other than Heracross, or Skarmory.
I haven't really looked into the possibility of stalling in this tier. I think it should be possible to use some kind of screen-based stall, although nothing would be reliable against Snorlax, and it would probably be pretty easy to counter team.