>>12013538Replace Confuse Ray with Thunder Wave
That way, you can support the rest of the team [and yourself], ease setting up Subs, and screw over opposing teams beyond a switch.
Leftovers on Umbreon. Focus Sash is a bizarre safety against Close Combats when you have 2 4x resists on your team. Also give it a Impish/Careful nature. I find Synchronize to be more useful overall, but up to you I guess.
Sigilyph would do better with Light Clay. Setting up the right screen should let you live long enough to set up everything else.
Weavile is interesting, but inefficient. Unless you REALLY need Aerial Ace, I'd replace it with Ice Shard. Priority really does help when it's as frail as it is. Low Kick may be better for you than Brick Break, due to the general heaviness of Steel/Rock Pokemon.
Yanmega also lacks a nature.
I don't see Wailord doing much of anything on your team. I'd recommend replacing it with something that sets up hazards, and perhaps even spins as well to support your SR weak team.
You can have a team designed to support Regigigas or Wailord [poor choice, as much as I like it myself; it just isn't a centerpiece], but not both.
Donphan adds a Rock resist that can set up Rocks + Spin, though it can compound an Ice weak. Forretress is what it is, again, up to you.