Armaldo is a pretty decent Pokemon. It has really good Atk and Def, but it Speed is pretty bad. It can fix that with Rock Polish and/or Swift Swim, though. Armaldo is a little limited. While it has a pretty good movepool, with EdgeQuake, X-Scissor, Aqua Tail, etc., it's basically going to be either a slow, defensive Sword Dancer/Choice, or a faster Swift Swimmer/Rock Polisher.
Anorith has decent Atk and better Spd than Armaldo, and could be used with Armaldo's SS/RP sets for a faster sweeper. It is much more fragile though, and can't use Stone Edge (although it can make do with Rock Slide).
Swift Swim Armaldo (or maybe even Anorith) could do well in Doubles/Triples, especially if paired up with a Rain Dancer. It can use Earthquake and Rock Slide, giving EdgeQuake coverage while being able to hit multiple opponents. It is weak to Rock Slide and Surf though, so be careful.
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