dhelmise is an underrated attacker both in and against trick room teams, with a base stat of 40 speed and 131 attack, along with respectable numbers in its defenses.

its typing allows for stab moves from power whip and poltergeist, with its steelworker ability additionally boosting gyro ball and anchor shot

anchor shot is useful in double battles for trapping opponents as well as dealing high damage with steelworker and life orb

gyro ball is effective in taking down fast attackers and is generally useful in trick room, and is also boosted by steelworker, allowing for potentially massive damage due to dhelmise's low speed. higher power can be guaranteed by using iron ball instead of life orb to reduce speed, but will remove the 30% boost in attack given by the orb

power whip is a strong attack and gets stab, letting dhelmise do a lot of damage
poltergeist is also strong and gets stab.

these moves are chosen to make the most out of dhelmise's high attack stat, boosted further by the life orb, its ability and types.

the ghost/grass typing is especially useful against common trick room pokemon, such as ursaluna, armarouge or hatterene

when paired with pelipper's drizzle and wide guard, dhelmise becomes more likely to stay alive as fire type threats such as mystical fire or torkoal are weakened