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.

Despite lacking STAB, Volt Switch outclasses both Bug Bite and Struggle Bug. It offers decent damage and great energy generation. However, Bug Bite can be ran if coverage against Psychic- and Grass-type Pokemon is desired.

Earthquake is a slow but powerful move that gives Forretress the much needed power and coverage against its only weakness: Fire-type Pokemon. Rock Tomb doesn't provide a lot of value for its high 60 energy cost, but its ATK debuff does synergize with Forretress's great bulk. Heavy Slam isn't a spectacular move, but its STAB damage and moderate 50 energy cost lets it be more accessible against specific targets. Mirror Shot and Sand Tomb moves aren't particularly strong and are mostly used for baiting shields. The former requires less energy with a 30% chance to debuff the opponent, while the latter costs a bit more energy but guarantees a debuff.