Struggling to Overcome Helping Hand Miraidon Nukes. Any tips?

I’ve been using Assault Vest Groudon as my Restricted in Reg G and feeling relatively safe until I started running into Farigiraf/Miraidon teams in Ultra Ball tier. One Helping Hand Draco Meteor was OHKO nuking Groudon easily, so I started leading with Tera Fairy Indeedee. But even then, Miraidon gets ahead of me by pivoting out with Volt Switch to reset its Terrain.

I feel like there’s no good options, as if I lead with Grimmsnarl for Light Screen or Misty Terrain, it’s still killed by Helping Hand Miraidon on the first turn; having both Indeedee and Rillaboom seems like overkill; and there’s no way to use priority/Prankster moves to delay Miraidon thanks to the Giraffe standing next to it. There’s also some unpredictability in whether Miraidon will be Tera Fairy or Electric, so it’s difficult to OHKO.

I’m sure there are tried and true strategies I should be utilizing, but I can’t see them in the face of Specs Miraidon’s immense power when it can constantly receive Helping Hand. Can anyone share their tips on taming this beast of a legendary?