Whiscash was sent out after Juan's Luvdisc was defeated. Ash's Corphish launched Bubble Beam, which Whiscash negated with Surf. With Rock Smash, Whiscash defeated Corphish. Ash sent Swellow, who started off with Quick Attack. However, Whiscash stopped the attack with its whiskers, then used Tickle on Swellow. While holding it, Whiscash launched Hyper Beam, which inflicted a lot of damage on Swellow. The latter, however, endured the attack and used Aerial Ace; Whiscash tried to dive, but Swellow dived in as well and hit the former. Whiscash swung by a pillar with its whiskers and launched Hyper Beam, but missed, due to Swellow's Quick Attack. Whiscash tried to dive once more, but was quickly defeated by Swellow's Aerial Ace.
Before arriving to Slateport City for May's Grand Festival, she and Ash remembered their past adventures so far. Ash recalled facing Juan, whose Whiscash surfed away and used Rock Smash on Ash's Corphish.