Here is the scene where G-Merl, Danielle, Sub-Zero, Raimundo and Clay helps the DigiDestined and their Digimon helps them out to fight the black creatures in G-Merl's Eternal Quest.
(Later, G-Merl, Danielle, Sub-Zero, Raimundo and Clay made it to the abyss until they saw the DigiDestined and their digimon being under attacked by the strange creatures)
Tai Kamiya: Man! There's to many!
Agumon: What should we do Tai?!
Dani Phantom/Fenton: What's going on down there?
Raimundo: I'm not really sure, but I think that's Tai and the others.
Sub-Zero: It appears that you can't hold off those warriors for long.
G-Merl: That's what they think, let's go!
Dani Phantom/Fenton: Right!
(Then they go in to help them out)
Takato Matsuki: It's no use!
Henry Wong: Looks like we're gonna biomerge!
(Then G-Merl, Danielle, Sub-Zero, Raimundo and Clay appeared and takes down the black creatures)
T.K. Takaishi: G-Merl!
Joe Kido: Thanks for saving us!
G-Merl: Is everyone okay? You guys are not hurt?
Cody Hida: No. We're all okay.
Matt Ishida: And who's that girl?
G-Merl: Her name is Dani Phantom. But you can call her Fenton. These are my friends the DigiDestined and their Digimon. These are Tai Kamiya. Davis Motomiya. Takato Matsuki. And Takuya Kanbara, four leaders of the DigiDestined.
Dani Phantom/Fenton: It's a pleasure to meet all of you.
Kari Kamiya: You too.
Gatomon: What are those things?
G-Merl: Black creatures. They are working with their master Black Doom.
Dani Phantom/Fenton: They're called "Black Arms"
Clay: Sounds like you partners might need our help.
Takuya Kanbara: You sure need our help.
G-Merl: Yeah. To find the seven Chaos Emeralds so I can discover my destiny.
Takato Matsuki: Alright then, you can count on us.
Guilmon: Yep. We will be really fighting machines against the black arms.
Tai Kamiya: Then we have to find them, let's go gang!
(The DigiDestined and their Digimon walk off with G-Merl, Fenton, Clay, Raimundo and Sub-Zero)