Tidal Rush

Tidal Rush is a song performed by DJ Octavio feat. Callie vs. Marie.

Description
Tidal Rush is an electronic remix of both of the Squid Sisters' solo songs, adding Tide Goes Out to DJ Octavio's remix of Bomb Rush Blush. Therefore, it has very similar production to the Bomb Rush Blush remix. It begins with Marie singing the chorus of Tide Goes Out over an orchestral violin intro. She then continues to sing the chorus, but faster and in a higher key to fit with the Bomb Rush Blush remix which fades in, before eventually, both cousins sing the chorus of their respective songs simultaneously. After an instrumental break, the two alternate lines from their respective songs before both of them simultaneously sing again. Finally, Callie sings her section on her own before the track loops. tl;dr looool

The song plays during Phase 3 of the final boss of Splatoon 2 and starts during the cutscene where Marie arrives to shoot Callie's Hypnoshades off. It plays throughout that portion of the fight, with the intro ending when the player regains control and stops playing during the cutscene at the beginning of Phase 4. It can also be heard in Squid Beatz 2 after hearing it in the final boss battle, with a maximum score of 235 and 402 in Normal and Hard modes, respectively.

Tidal Rush (Splatune 2)
During the final boss battle, the drumbeat of the song is played on its own before Marie starts singing to help transition from Bomb Rush Blush. This beat is also added to the version used in Splatune 2 as Bomb Rush Blush plays before it.

Trivia

 * Tidal Rush and DJ Octavio's remix of Bomb Rush Blush are currently the only instances of songs with featured artists in the series.
 * The listed performers of "DJ Octavio feat. Callie vs. Marie" is a reference to the Splatfest of the same name, which also pitted the two cousins against each other.
 * Tidal Rush is the only song by the Squid Sisters that has not yet been performed live.

Etymology
Tidal Rush is a combination of the titles of the songs remixed, Tide Goes Out and Bomb Rush Blush.