As we saw from the threats nomination, this core mainly struggles with fast attackers and annoying bulky Grass-types such as Tangela and Gourgeist, so I thought about Roselia, as it can help with many problems this core has. First of all, as this core doesn't have a great typing synergy and is purely offensive, it needs a sort of backbone that can tank hits, Roselia can do that pretty well. Roselia alsoprovides Toxic Spikes support, which heavily cripples bulky Grass-types, such as the ones I listed, and walls in general that can switch on Sawsbuck and Stoutland, and can absorb Toxic Spikes itself, which can be annoying to this core, as it lacks recovery. This core is also not that fast without sun support, so Roselia, thanks to its access to Stun Spore, can spam paralyses and therefore ease the job of the core in sweeping, while if running Sleep Powder, can create free switch opportunities for teammates, which can be lethal, especially against a core that threatening offensively