>>30995709Nihilego also has Toxic Spikes, so between it and Toxapex I think it's pretty reasonable to assume that Toxic Spikes will be more common.
Gengar can now absorb them if needed.
>>30995760I imagine that since Gengar doesn't have much bulk, it could say, take advantage of both Grassy Terrain and Black Sludge in tandem with Substitute. I don't think Cursed Body will work with Substitute unfortunately, but I'm sure a SubDIsable set could still find use.
I do still feel like it's a trade off. What are some Pokemon (with Ground type moves) that Gengar would be able to switch into before? If it was say, Excadrill, to block its Rapid Spin, doesn't it usually carry Iron Head as well? Gengar's not living through that. Unless Excadrill is usually Choiced or something. Gengar also still has two other immunities to take advantage of, and doesn't it have some 4x resists? To Poison?