This is how CYLAS becomes a Terrorcon goes in Thirst.
[The Nemesis flies through a cloudy sky]
Knock Out: Two additional doses, three at the most. But CYLAS' increasingly volatile nature isn't the only wrinkle. It appears that the more green stuff I administer, the faster this monstrosity formerly known as Breakdown burns through his own natural Energon reserves.
Starscream: This will not do! Megatron already possesses one unruly beast, with that Predacon of his! What good is another freak of nature that cannot be controlled?
[He suddenly gets an idea]
Starscream: Wait! I'm a fool.
Knock Out: Dark Energon?! You are more than a fool, Starscream! I think your neural cluster has blown a massive fuse!
Starscream: Oh, on the contrary, dear Doctor. Adding Dark Energon to the formula should provide Lord Megatron with full control over his supersoldier.
Nightmare Moon: Trust us.
Tempest Shadow: It will be natural.
Queen Chrysalis: And more fear-striking.
Knock Out: Okay. True that Lord Megatron seems to possess a symbiotic link to any-one or -thing infused with the dark matter, allowing him to manipulate them as if they were puppets, but have you forgotten what the so-called "Blood of Unicron" did to our warship?
Starscream: That was the result of a massive infusion. I am suggesting a drop or two merely enough to allow our Master to command his warrior at will.
Nightmare Moon: He's experienced it once.
Tempest Shadow: Now it's your turn.
Queen Chrysalis: Just trust us on this one.
[CYLAS' optics snap open and he roars]
Knock Out: It's alive!
[CYLAS breaks free of his ties]
Knock Out: Aah! Oh!
[CYLAS gets up, takes a few steps then collapses]
Knock Out: Scrap!
Starscream: Oh, for the love of now what?!
Nightmare Moon: Yes, Knock Out.
Tempest Shadow: What happened?
Queen Chrysalis: Why didn't he move any further?
Knock Out: I tried to tell you before it's a side effect of the Synth-En. He's burned through his own natural reserves.
Starscream: Then perhaps we should withhold any infusions for a while might calm Cylas down a bit, make him a tad more manageable...
[CYLAS starts shaking]
CYLAS: Need Energon.
[He produces an Energon-sucking Terrorcon tongue from his lower jaw]
[He approaches Starscream and tries to drain him]
[Knock Out zaps him with his prod from behind]
[Nightmare Moon bucks him and CYLAS again produces the Energon-sucking tongue]
Starscream: Do you think he's actually trying to--
Knock Out: Suck out our Energon with that thing?
[CYLAS stretches his tongue]
Knock Out: Sure seems that way.
[CYLAS takes the prod and breaks it]
[The cons and ponies run into a hall]
[Starscream turns to Knock Out]
Starscream: See if you can hold him off!
Knock Out: W-what?! Wait for me!
[Starscream transforms and Knock Out holds on]
[CYLAS stops and turns and walks away]
[In another hall, Starscream transforms to bot mode throwing Knock Out off]
Knock Out: We need to sound the alarm!
Starscream: Out of the question! Megatron will undoubtedly hold us responsible.
Nightmare Moon: He's right.
Tempest Shadow: Who knows what he'll do to us then.
Queen Chrysalis: This would be seen as act of betrayal.
Knock Out: But we are!
Starscream: Well, you are, mostly. Anyway, his lordship doesn't need to know that not if we handle this the right way.
Nightmare Moon: Good thinking.
Tempest Shadow: That's right.
Queen Chrysalis: CYLAS won't last three minutes.
Knock Out: Meaning?!
Starscream: Use your head, Knock Out! This ship is crawling with highly trained Vehicon troopers, armed for combat. The moment CYLAS attempts to feed, they will neutralize him for us. Problem solved.
Nightmare Moon: Trust us.
Tempest Shadow: This is better than all of Starscream's previous ideas combined.
Queen Chrysalis: You'll see.
[Meanwhile, a Vehicon is roaming the halls. CYLAS jumps on him and drains his Energon]
[With Knock Out, Starscream, and the pony villains]
Knock Out: Once we recover CYLAS' body, we must dispose of it as quickly and efficiently as possible. No trace of him can be allowed to remain.
Starscream: His infected body.
[They turn a corner and see the dead Vehicon]
[Knock Out runs over]
Knock Out: Gone. Completely drained of Energon. Tell me something, Starcream when you said "problem solved," is this even close to what you had in mind?!
Starscream: I do not appreciate your tone, Knock Out. This brewing catastrophe is hardly my fault.
Nightmare Moon: Hey!
Tempest Shadow: This was your idea to begin with!
Queen Chrysalis: Yeah!
Knock Out: Well, it certainly isn't my fault!
[As they bicker, the Vehicon gets up]
Starscream: Oh, no? You're the Mastermind who chose to experiment with Synthetic Energon.
Knock Out: And you're the monkey wrench who thought it was a good idea to dabble in voodoo!
[The Vehicon growls and they freeze]
[They turn to face it]
[It produces the same tongue as CYLAS]
[Knock Out and the others back off in horror]
Starscream: I thought you said he had no spark!
Knock Out: Dark Energon it reanimates the dead!
Knock Out: Aim for the head!
Starscream: What?! How do you know?!
Knock Ouf: I have seen equine horror films!
Knock Out: At drive-in theaters!
[Starscream puts his gun away]
[He aims his missile at the Terrorcon]
[He fires and the head is blown off but the Terrorcon continues its advance]
Starscream: Forget the head! Go for the spark!
[He shoots the Vehicon in the chest multiple times]
[It collapses and the cons put their weapons away]
Knock Out: We severed its link to the Dark Energon. Equine horror films waste of time.