Core 1 because NP Thundorous is my favorite Pokemon
Helioisk is not on the viability list. Sorry for the inconvenience but we are gonna need replays if this one is to be accepted
Cofagrigus @ Leftovers
EVs: 252 HP / 252 SpA / 4 Def
IVs: 31 HP / 0 Atk / 30 Def / 30 SpA / 30 SpD / 0 Spe
-Hidden Power Fighting
Lopunny's worst nightmare - it can't do that much damage without High Jump Kick to it and using any of its physical moves strips its ability to really damage it. It's also bulky enough to stomach hits from Landorus-T and cripple it with a burn - if it lands one on T-Tar, it's no longer OHKOed by a boosted pursuit. Furthermore, Latias and Jirachi are both 2HKOed by Shadow Ball. While Trick Room does not benefit Heliolisk very much, it does allow Cofagrigus to get the jump on whatever wants to switch in.
Heliolisk @ Life Orb
Ability: Dry Skin
EVs: 252 SpA / 4 SpD / 252 Spe
IVs: 0 Atk
An actual counter to Manaphy! It can switch in, take a +3 Energy Ball if needed and always OHKOes with Thunderbolt. Other than being a very good way to deal with Manaphy, it can 2KHO Tyranitar with Grass Knot and 2HKO Latias and Landorus-T with Hyper Voice. It also outspeeds anything on that team outside of Latias and Mega Lopunny, a Timid Nature is not needed to achieve this - also, a Modest Nature guarantees the OHKO against Manaphy.
Bummer, I was mainly in it for the theorycrafting. In that case, I'll just pull back from this, but I want to leave the sets up in case someone else wants to compete with those (my sets being basically just hard counters to M-Lop and Manaphy respectively).Helioisk is not on the viability list. Sorry for the inconvenience but we are gonna need replays if this one is to be accepted