This is how Shining Armor vs Mixmaster goes in The Crystalling Part 2.
[Shining Armor sees Mixmaster mercilessly beating Twilight on the floor]
Shining Armor: Twily!
[Mixmaster stops then turns around]
Shining Armor: Let her go, Mixmaster!
Mixmaster: Sure thing, Shining Armor.
[Mixmaster carelessly throws Twilight to a wall]
Mixmaster: Now it's your turn.
[Mixmaster pounces on Shining Armor and they start fighting]
Mixmaster: How do you expect to defeat me if your little sister couldn't?
Shining Armor: This! [uses his magic to freeze Mixmaster's feet to the floor]
[Mixmaster breaks free and transforms to cannon mode]
Mixmaster: I can keep this up all day! [fires at Shining Armor]
Shining Armor: Not if this happens! [uses his magic to clog Mixmaster's cannon]
[Mixmaster transforms to robot mode]
Mixmaster: Ugh! What does it take to defeat you?!
Shining Armor: It would take a hundred of you guys to take down the Captain of the Royal Guard!
[Mixmaster picks up a crystal]
Mixmaster: Here--catch! [throws the crystal at Shining Armor]
Shining Armor: Oh, no, you don't! [creates a forcefield, which the crystal bounces off]
[Mixmaster groans in frustration]
Mixmaster: Die, Unicorn! [goes to ram Shining Armor]
Shining Armor: Uh-uh! [dodges and Mixmaster hits the the wall, knocking himself out]
[Mixmaster recovers and gets up and Shining Armor fires beams of magic at him]
[Mixmaster falls to the ground, defeated. Shining Armor approaches him and looks down]
Shining Armor: That was for Twily. And this is for trying to harm Flurry Heart!
[Shining Armor bucks him in the head and knocks him out]
Shining Armor: [goes over to Twilight] Are you alright, Twily?
Twilight Sparkle: I think so. Thanks, Shining.
Shining Armor: Anything for my LSBFF.
Twilight Sparkle: "Little Sister Best Friend Forever"?
Shining Armor: Yeah.
Twilight Sparkle: Thanks.
[They hug and Mixmaster gets up, more angrier than ever]
Mixmaster: I'll rip you to shreds!
[Mixmaster is about shoot them when Optimus shows up and shoots him from behind, killing him]
Optimus Prime: When will you Constructicons ever learn?
[Optimus goes over to Twilight and Shining]
Twilight Sparkle: Great job, big fella.
Shining Armor: Now let's go help the others.
Optimus Prime: Agreed.
[They head off to help the others]