I won't lie skarm + reuniclus looks like a terrifying fat core in this meta, as spikes help Reuniclus wearing down its checks, on top of Skarm being a good Pokemon in defensive teams in general. SD Bulu and Darks might be fine checks to Reuniclus, but i'm not really sure if the Tapu wins against double dance, and the darks lose to colbur focus blast. I think taunt madness fini or even taunt cm might be annoying for reuni, even though it doesn't want to take boosted Thunders, especially if spikes are up.
Take this with a grain of salt though, i still have to get experience in this metagame lol