What it does
Aqua Step deals Water-type physical damage and raises the user's Speed by one stage on every use — no RNG, every hit. That distinction matters: you're not hoping for a Speed boost after attacking, you're getting it every single time you click the move.
Speed in doubles controls turn order, and turn order determines whether you move before your opponent's attack lands. Stack Aqua Step twice and you've outrun almost everything that isn't using a priority move or a speed-inverting field effect. Water coverage handles Fire, Rock, and Ground — all relevant in the current format.
Who runs it
Quaquaval at 85% is the defining user. Water/Fighting typing gives it two strong STABs — Water for the straightforward coverage, Fighting for Normal, Rock, Steel, and Dark targets. Its base Attack is high, and the Speed stacking from Aqua Step turns a strong physical attacker into a hard-to-outpace cleaning threat.
How to use it
Click Aqua Step turn one. The earlier the Speed advantage is established, the longer it compounds. At +1, you're faster than most of the metagame's common Speed tiers. At +2, you're outpacing dedicated fast threats that don't run Speed control.
The doubles value is priority of target selection — moving first means you pick who gets hit before the opponent can respond. A fast Quaquaval threatening a 2HKO on the opponent's support Pokémon changes what moves they can safely make.
Bring teammates that handle Grass-types and Electric-types. Those are Quaquaval's main offensive checks, and its Fighting subtype creates Psychic and Flying weaknesses too. Cover those in team building so Quaquaval can focus on accelerating.
Tips & strategy
Priority moves bypass Speed entirely — Extreme Speed, Sucker Punch, and similar options hit before Speed-boosted Pokémon can act. When the opposing team has reliable priority users, don't assume Speed +2 makes you safe. Plan to remove those threats first.
The window before Aqua Step lands its first boost is the most dangerous period for Quaquaval. If you can't guarantee survival through turn one, partner support (Fake Out, redirection, or speed control) bridges that gap.
After boosting, Quaquaval's Fighting coverage for cleanup is the plan — Water for the obvious targets, Fighting for whatever hides behind Normal or Steel typing. Opponents stalling with Protect don't eliminate the Speed gap, they just delay the same problem into the next turn.