Gengar help pls

[T_Rex2k6]

What is the best held item for Gengar in Pokemon Ultra Moon?
Thanks in advance
Moveset:
Giga Drain
Shadow Ball
Psychic
Thunderbolt

 

[Levea]

For this set a choice item might work for you ( assuming you are playing OU) specifically choice specs if you want a wall breaker or choice scarf if your team needs something to speed-creep things.

 

[Dark Azelf]

Thunderbolt, Psychic and Giga Drain offer little to poor additional coverage so have little justification warranting a place on any set imo. Sludge Wave, Focus Blast and Substitute, Taunt or Destiny Bond @ Black Sludge, Fightinium Z or Life Orb are better. Focus Blast is necessary to OHKO Dark-types such as Hydreigon, Krookodile, and Bisharp. It can also be used with Fightinium Z to have a powerful, perfectly accurate Fighting-type move. Sludge Wave hits the fairy types that are common place, it also a nice secondary STAB move. Sub is useful to scout switch ins, especially those with Pursuit or scarfers. Taunt shuts down walls whilst Destiny Bond can grab you a quick kill.

A bulkier gengar set with sub, pain split, hex and will-o-wisp is also cute and annoying.