This is how Drift the Autobot shares his story of Yoaki in Thomas and Twilight Sparkle's Adventures of Big Hero 6.
[Our heroes all tower over a badly damaged Red Alert, staring at him. Hot Shot then sadly sighs]
Hot Shot: I can't believe Red actually sacrificed himself to save us.
Clocker: Yeah. He was a brave friend.
Optimus Prime: And a noble warrior. Red Alert, we will never forget you.
Thomas: When push came to shove, you really were brave fighting that unknown villain. [lets a few tears drop from his eyes]
Landmine: [turns to Drift] Yo, Drift. You don't mind tellin' us who that villain we were fightin' back there was, do ya?
Drift: [sighs] Alright. If you guys want the truth, here it is. His name is Yoaki, he was the one who betrayed me eons ago. The one who made me suffer. I once was a pupil of his, until he turned evil and fought against me. And I've been wanting revenge ever since.
Vector Prime: It appears that Drift has been out for revenge on Yoaki in order to restore their friendship.
Rainbow Dash: So, what do we do now?
Hot Shot: I'll tell you what we're gonna do. Because we're not gonna let Red Alert die in vain. We're gonna get out there, save the city, and we're gonna take those Microbots down! Ya with me?
Clocker: I'm in.
Thomas: Me too.
Rainbow Dash: Count me in.
Scootaloo: We're in too.
James: All of us are in.
Hot Shot: THEN LET'S DO THIS!!!!!!!!
Thomas: Hiro! Baymax! Will you two take care of Red Alert?
Baymax: Whatever's best for you, Thomas!
Thomas: [activates his wings and takes flight] Let's go! [rockets off]
Hiro Harmada: Do you think Red will be okay, Baymax?
Baymax: I'm not sure, Hiro.