Weezing

Poison is already one of the least prevalent types in the game, exacerbated by the meta’s lack of Grass and Fairy-types. Even among other Poisons, Weezing is outclassed by the likes of Victreebel and Tentacruel. As such, it has been relegated into a tank role, in which it is further crippled by the absence of its usual Ground-type immunity.

PoGO has not been kind to James’s classic buddy, but to its credit, Weezing has a defensive movepool well tailored for counter coverage, making the most of a bad situation.

Best PvE Offensive Moveset

• Acid* offers the highest DPS with STAB, but is a legacy move.

• Infestation fits into Weezing’s role as a Grass-type killer.

• Tackle is inferior in every way.

• Sludge Bomb is preferred for its STAB effectiveness against Grass-types

• Shadow Ball is clearly superior to Dark Pulse; both share the same cooldown and coverage, but the former simply deals higher DPS.

• Thunderbolt can offer coverage in some niche situations, but lacks STAB. 

Best PvE Defensive Moveset

• Infestation is preferred for its ability to hit incoming Psychic-types.

• Acid* is clearly superior to Tackle; both offer wide neutral coverage, but Acid’s defensive DPS is significantly higher.

• Shadow Ball deals higher DPS, but Dark Pulse’s damage window is a whole second earlier, increasing the chances of it actually connecting. Both offer valuable counter coverage against Psychic-types.

• Sludge Bomb is a strong alternative, possessing an early damage window and wide neutral coverage.

• Thunderbolt offers coverage but has a slightly longer damage window than Dark Pulse or Sludge Bomb. 

Infestation is Weezing’s only fast move that doesn’t suck, so it’s the fast move of choice. Sludge Bomb is a must for solid STAB damage.

As for Weezing’s second charged move, you’ve got some options. Shadow Ball  gives incredible neutral coverage, and Thunderbolt gives you a better matchup against Skarmory. Dark Pulse doesn’t provide much coverage that Shadow Ball doesn't, so it's not typically worth using.