Shadow Forretress

Forretress is a Pokemon that doesn't really benefit from the shadow boost. Its loss in defense is far greater than what it gains in attack, and said attack boost just doesn't matter enough to be note-worthy. If you're going to raise a Forretress (for Defense or PvP... not for offense), then it's probably better to raise the non-shadow version.

Best PvE Offensive Moveset

• Bug Bite is strictly superior to Struggle Bug in every respect.

• Heavy Slam is the only STAB charge move that Forretress learns, and is itself a decent 2-bar move.

• Rock Tomb and Earthquake simply don’t work.

Best PvE Defensive Moveset

• Struggle Bug performs better on defense due to high defensive DPS.

• Heavy Slam and Rock Tomb, both 2-bar moves, are preferred, as they are likely to be used at least once.

• Rock Tomb has coverage vs. Forretress’s biggest enemy: Fire-types.

• Earthquake is not worth mentioning.

Bug Bite deals heavy damage and benefits from STAB. However, Volt Switch can be used for greater energy gains and additional coverage. Struggle Bug is bad.

Rock Tomb is an amazing Charged Attack and covers against Fire-type Pokemon. Its Attack debuff synergizes well with Forretress's terrific bulk. Sand Tomb is an underwhelming move, but its Defense debuff and low cost pairs well with Bug Bite's high damage. Earthquake can be used over Sand Tomb to dent bulkier targets. Mirror Shot is Forretress's cheapest option, but its damage is very lacking despite benefiting from STAB. Heavy Slam and Return aren't really worth running.