What kind of role does drapion have and in what kind of set does it translate?
Drapion was most commonly seen as a decent offensive check to Psychic and Ghost types like Chandelure, Polteageist, Gardevoir, Indeedee, that could spread Toxic or Toxic Spikes, use taunt to annoy defensive POkemon, and had access to Knock Off which was uncommon before Pokemon HOME released. A set like this was pretty common,
Drapion @ Black Sludge
Ability: Battle Armor
EVs: 248 HP / 44 SpD / 216 Spe
Jolly Nature
- Knock Off
- Toxic
- Toxic Spikes
- Taunt
The speed stat was changeable, depending on what sort of things you wanted it to check. 216 Speed EVs let it check roserade better, but you could also drop it down to 184 EVs to outspeed rotom forms, or 136 EVs to only outspeed Chandelure. Some variants may also have opted to run Poison Jab over one of the two status moves.
Some other sets were used such as Scarf and Swords Dance, but these utility sets were the most common.
In general after Pokemon home however, drapion has lost a lot of it's uniqueness, with Toxic and Knock Off becoming more widespread. This leaves it as more of just a general check to Pokemon like Chandelure and Polteageist that can provide some utility to a team and a toxic spikes absorber / toxic immunity, but would be relegated mainly to more offensive teams as defensive teams have plenty of options as far as Toxic goes and have less need of drapion now.