[Gen 8] Monotype - Normal
Porygon2 @ Eviolite
EVs: 252 HP / 252 Def / 4 SpA
IVs: 0 Atk
- Thunder Wave
- Ice Beam
This is the set I use in Gen 8 Monotype. Porygon2 is one of the better defensive Pokemon for Normal teams, and I use Eviolite plus max HP and Defense to make it a solid physical wall.
This set differs a bit from other Porygon2 because it takes a slightly more offensive approach -- with a Modest Nature, Ice Beam, and 4 Special Attack EVs, Porygon2 can always OHKO Landorus-Therian after a Download boost. It has the benefit of also hitting Pokemon like Rillaboom and Garchomp, which Normal teams can struggle with otherwise.
The rest of the set is fairly standard. Thunder Wave hinders setup sweepers, fast Pokemon like Weavile, and Steel types; Toxic is preferred to whittle down bulkier Pokemon. Recover promotes Porygon2's longevity and allows it to stay in for longer.
This set does sacrifice a bit of bulk in favour of being able to remove Lando-T from the field. It would need to sacrifice even more in order to always kill Landorus without the Download boost, but relying on Download generally gets the job done.