Thundurus-Therian (M) @ Heavy-Duty Boots
Ability: Volt Absorb
EVs: 8 Def / 252 SpA / 252 Spe
Timid Nature
- Thunderbolt
- Psychic / Focus Blast / Grass Knot
- Knock Off
- U-turn
This is overall regular Thundy-I but worse but it brings an appreciable volt immunity in some scenarios and the ability to lure a few mons that'd come to check np Thund-T but wouldn't appreciate pivot, Chansey is one of those (can also work p well on Tang/Zarude/Nihi/Heattom pivoting in). Chansey would usually like to come in on nasty plot to proceed to tox/soft boiled Thundy to death (even if it means having to sack something, it's a consistent way to get rid of it), and will probably never switch out against an unboosted Thundurus-T early on.
Knock-Off is close to an OHKO move on Chansey, making it lose a considerable amount of bulk. Once it's knocked you even get the chance to 2hko it after chip if you feel like it by running Focus Blast but honestly it's unneeded, as long as it's knocked most of your team that isn't an Amogus should be able to power through it in the long run.