Here is how the signal he sent up and recruiting Ozai goes in Ryan F-Freeman's Adventures of Transformers: Prime.
[At the Autobot base, everyone was relaxing]
[we see Sonata and Aria playing the racing game, and that Sonata is winning somehow]
Ryan F-Freeman: Wow, Sonata.
Human Rainbow Dash: Not enough power, Aria. Speed up.
Evil Ryan: C'mon, Aria! I hope you like Ryan.
[Ryan winks at Aria and Ryan polishes Evil Ryan's pendant]
Foduck: Go on! And be safe while doing so.
Sci-Ryan: I did know these Equestrian Sirens can absorbs negative energy and distrust of others.
[just as Aria was about to ram her younger sister off the road, Sonata hit the brakes and Aria flew off the road instead]
Sunset Shimmer: That is the oldest trick in the book.
(the alarm suddenly went off]
Bulkhead: What's the problem?
Ryan F-Freeman: We'll find out.
Ratchet: It seems it's an energy surge coming from Cairo. Right here to be precise.(points to a certain location)
Fowler:(on Comm system) Prime, do you copy?
Optimus Prime: I am here Agent Fowler.
Fowler:(on Comm system) Just to alert you, the Pentagon isn't the only one onto the energy surge as well.
Human Applejack: Yeah, we know. The Cons are onto it as well.
Fowler:(on Comm system) Of course they're gonna be onto it too. But I mean Fury is going and he is bringing two assets with him.
Ryan F-Freeman: We could go there.
Ratchet: Their names?
Crash Bandicoot: What are their names, Fowler?
Fowler:[on Comm system] That's the reason that has me worried about the surge. Their names are Professor Charles Xavier, founder of the Xavier Academy, and Erik Lensherr, who as you all know, has quite the reputation.
Sci-Ryan: Like Crystal Prep?
Fowler: [on Comm system] Worse than that. Lensherr goes by another well known name. He calls himself Magneto, the Master of Magnetism. Xavier on the other hand, lost the use of his legs. But that doesn't mean he isn't dangerous. That's why the Pentagon wants us down there immediately.
Optimus Prime: We're on our way.
Fowler:(on Comm) Fowler out.(hangs up)
Ratchet:(opens the groundbridge and transforms)
Optimus Prime: Autobots, roll out!
(they do so)
Ryan F-Freeman: Ok, Sci-Ryan. Your magic can handle Magneto's powers.
Thomas: What do you want us to do, Optimus?
Sci-Ryan: Tell us what to do and we'll do it.
Optimus Prime: Ryan, Thomas, you come with us.(to the Dazzlings) You three as well. Magneto can control metal. In 1983, he caused global destruction by manipulating Earth's magnetic field. If Director Fury is bringing two of the most powerful mutants with him, the surge must be mutant related. And as it was in Egypt, it cannot be anything good.
Thomas: Okay.
Evil Ryan: My 2 friends and I can come too.
Thomas: Optimus, I'm still struggling with my true origins. What if the Cons find out I exist?
Ryan F-Freeman: Might as well.
[they all enter the groundbridge]
[on the other side, they see two helicopters land, one of them belonging to Fowler]
Matau T. Monkey: Hi, Fowler!
Fowler: Hey. Now everyone, I'd like to you all to meet Director Nick Fury of S.H.I.E.L.D, Charles Xavier, and Erik Lensherr.
(three men stepped out of the helicopter)
(one was black in color and had an eyepatch)
(the second was in a wheelchair, and was bald)
(the third man had a working beard growing in, a coat, and a hat)
Crash Bandicoot: Professor X. In the flesh.
Optimus Prime: Well, hello, gentlemen.
Evil Ryan: Nick Fury. I'm happy to see you.
Ryan F-Freeman: My name is Ryan, Nick Fury.
Thomas: I'm Thomas.
Bertram T. Monkey: Bertram. Matau's twin brother and bandmate of the Cyberlings.
[After the others introduce themselves, Fury speaks]
Nick Fury: Look, it's nice to meet you all, but where exactly did the surge take place?
Ratchet: Over there.(points to a place it's metal sticking out of the ground)
Erik Lensherr: It cannot be.
Charles Xavier: I know Erik. I know.
Sonata Dusk: What can't be?
Evil Ryan: What's this?
Erik Lensherr:(removes hat) This is where we destroyed Nur in 1983.
Charles Xavier:If he has returned, the world is in very real danger.
(this shocks everyone)
(meanwhile, in the Fire Nation Capital's prison)
Ryvine Sparkle: Why have I sent here? No one puts Bad Sofia in a barn.
[Bad Sofia was in a cage too]
Ozai: Would you be quiet?
Guard: Why don't you both be quiet?
(suddenly a hooded figure appears from the shadows)
Ryvine Sparkle: What the? Who are you?
(the figure raises his hand and dust goes across the guards neck, killing him)
(he sinks Ryvine into the ground, stuck)
(he then puts Bad Sofia in the wall)
Apocalypse: I have been called many things over many lifetimes.(unlocks Ozai's cage) Ra, Chrishna, Yaweh.
Ryvine Sparkle: [uses his magic to get out of the ground and teleports Bad Sofia and himself out of the scene]
[Ozai stands up, but can't find the strength to fight]
Apocalypse: There is no need to fight me my child.(puts his hand on his head) I am your ally. And I will return what was taken from you.(restores his bending and Ozai is in a more redder version of his robes, and has Orange skin)
Ozai: What have you done to me?
[at the Nemesis]
Megatron: Knock Out, have you found out anything about this mysterious surge?
Ryvine Sparkle: Lord Megatron! Bad Sofia and I fled with our lives!
Knock Out: Ryvine, do not interrupt. Easy my liege. With the help of Soundwave here, the one who made the surge was half human and mutant.
Megatron: Then he may be useful to us.
Bad Sofia:(raises her hand)
Megatron: Yes?
Ryvine Sparkle: Go on, tell him.
Bad Sofia: That's just it, Lord Megatron. He's back. Nur, has returned.
Ryvine Sparkle: Maybe you should call him Apocalyspe.
Megatron: Well, then this will prove problematic. However, he will not be threat to us.
Knock Out: Then how do we approach him without him killing us with dust?
Starscream: There are other ways he can kill, without dust.
[the screen goes black]