0073 Tentacruel

Poison Jab and Acid both benefit from STAB, but the former is superior.

Due to the large amounts of energy needed for Tentacruel's charge moves, Acid Spray is recommended for its lesser energy cost, which helps to bait shields in addition to its debuff utility. Sludge Wave doesn't offer any additional coverage, but costs less energy than other options and hits hard with STAB. Hydro Pump can deal massive damage with STAB, and is more preferable against neutral opponents. Blizzard can be elected for coverage against popular Dragons and Flying-types. The addition of Scald following the September 2022 update gives Tentacruel a slightly cheaper option than other available Charge Move options, but its damage threat is not as high. 

Tentacruel has a niche as a unique anti-meta specialist, sporting above average bulk, and a defensive Water/Poison typing. While its Poison moveset offensively doesn't provide a lot of value, Tentacruel's reputation largely comes from its nuke-style plays. Access to very hard-hitting charge moves makes Tentacruel very threatening, though only when shields are down. This limits its viability in the early game due to possible inconsistencies with baiting shields. Positive matchups against common picks like Azumarill and Registeel are definitely a plus, but at the cost of losses against various other meta Pokemon. 

Tentacruel needs some XL candy to reach the CP cap of Ultra League. Just like in Great League, its role in Ultra League as an anti-meta specialist makes it somewhat niche, with clean wins against a very specific group of Pokemon, and losses against the rest of the meta. Blizzard is needed to defeat Giratina, while Hydro Pump is mandatory to have a chance at Galarian Stunfisk. The buffs to Poison Jab and Acid Spray following the GBL Season 8 update considerably improves Tentacruel's performance in the meta, but choosing between Blizzard or Hydro Pump makes it less solid overall. 

Tentacruel is too weak for the Master League.