This is how The Sirencons get the Magic of Friendship from the Mane Six goes in The Endgame.
[The Sirencons get ready to drain the Mane Six of the Magic of Friendship as the Mane Six are sitting in a six-seated chair unconscious as they're still facing upward]
Harmo: Oh, how we've waited for this moment.
Sympho: Their magic will bring our powers to the next level.
Demo: Soon we'll be even more powerful then the Trix.
Sympho: You got that right.
Harmo: Let's do it. Ready, boys?
[They begin to harmonize]
[The Magic of Friendship comes out of the Mane Six's chests and into the Sirencons' cores]
Sympho: At long last, the Mane Six no longer possess the Magic of Friendship.
[Their powers increase]
[The Magic of Friendship is drained to the last drop as the Mane Six's unconscious bodies collaspe to the floor]
Harmo: Well done, boys.
Demo: Let's go give Starscream the good news.
[They head off to do so]
[They find him on the roof]
Harmo: Lord Starscream.
Sympho: We got the Magic of Friendship like you asked.
Demo: The job has been done.
Starscream: Excellent work, you three. I am certain the Autobots will be here soon to rescue their pony allies.
[The Autobots soon arrive on cue]
Optimus Prime: Starscream, where are the Equines?
Starscream: They're here, Prime. Just waiting for their humble friends to rescue them.
[The Autobots head inside and find the Mane Six unconscious on the floor]
Optimus Prime: Twilight! Girls!
[They run over]
Optimus Prime: Twilight.
[She wakes up]
Twilight Sparkle: [groans] Optimus, they took the Magic of Friendship.
Optimus Prime: We know.
[He helps her up]
Starscream: Wait, you're still bonded. But how?
Optimus Prime: Even though the Magic of Friendship has been lost, our friendship is what remains.
[Optimus seems to glow as he turns]
Starscream: How is this possible?
[The other Autobots glow as well]
Starscream: Not possible.
[They shoot a rainbow at him]
[He is blasted to parts unknown]
[The Sirencons are too hit and blasted to parts unknown too]
[The Autobots stop glowing]
Optimus Prime: The Magic of Friendship.
Twilight Sparkle: It's returned.
[The Magic of Friendship returns to the ponies]
Twilight Sparkle: Thanks.
Optimus Prime: No problem.
[They return to the Autobot base]
[Princess Celestia arrives]
Princess Celestia: I do not know how I will be able to thank you all.
Optimus Prime: The only way you can thank us is with guidance to how we master our Sirenix.
Princess Celestia: Very well.