I'm actually tempted to support Tyranitar, the synergy with Gliscor seems interesting, and the fact that most of the checks to our actual threats are covered quite well by CBTar is nice too. I'd consider running enough speed to outpace Jellicent, which is a major annoyance right now, but I guess we can do this kind of fine tuning later in the process.
However for the sake of variety, I'm suggesting Mamoswine.
Mamoswine @ Life Orb | Thick Fat
Jolly | 4 HP / 252 Atk / 252 Spe
- Earthquake
- Ice Shard
- Icicle Spear
- Superpower / Stone Edge / Stealth Rock
Mamoswine covers most of the threatening pokes that were listed if we decide to go for HP Electric. Salamence, Dragonite suddently aren't an issue anymore, and Lati@s must be very careful to avoid dropping into Ice Shard's KO range. Most Celebi sets are slower, thus gets wrecked by STAB SE Icicle Spear, Venusaur is checked since again LO recoil can quickly drop it into Ice Shard's KO range, and is destroyed by Icicle Spear anyway if we can pass an intact Sub somewhat. Amoonguss is similar to Celebi. While Reuniclus and Gengar can't be defeated directly, they don't like, respectively, strong Earthquakes and priority, thus it's not even that bad in that case, adn we still have half a team to cover those two pokes.
It's also interesting how Gliscor can act as a "safey blanket" for Mamoswine while trying to revenge dangerous physical and faster threats, like DD Mence / ScarfMoxieMence / DD Dragonite. Gliscor can safely switch in those threats, then "dry pass" to Mamoswine while taking the boosted hit (or taking two Outrages, in MoxieMence's case), which can then OHKO with Ice Shard. This reduces the risk of having Mamoswine Koed by an Outrage / Superpower on the switch to zero, and allows us to lose no pokemon while stopping their sweep cold.
Mamo also adds a degree of flexibility in our future choices, since we're not forced to find a SR setter anymore (if we're starved for team slots, Mamo can set up SR for us).
The bad part is that Mamoswine stacks Water weakness with Gliscor and Grass weakness with Keldeo. This can be an issue to an extent, however with still half of the team to be picked it still can be fixed easily, for example with a Dragon of some sort.