Alternate Ending: Warning very Dark, Graphic, Main Characters die, and poorly done Read at own risk.
What if the Elements of Harmony had no effect on Blitzwing like Discord's magic had no effect well here is what would happen in The Twilight Zone.
As the Elements of Harmony stopped non of the Mane 6 were hit by falling bricks and infront of them was a pile of rubble, " Is it over is he dead" Asked Prowl "No the Elements of Harmony do not kill anyone ponies and bots" Said Celestia "Then what happened to Blitzwing" Said Derpy when all of the sudden the rubble was moving when suddenly a hand came out it was the size of a Cybertronian's and then Blitzwing with the Hothead personality came out "You thought those things would work on me ha they were no match for me and because you disobeyed me you will all die" Said Blitzwing got up and charged his cannons when Prowl threw stars at Blitzwing which somehow he dodge "That won't work on me but now taste my Ultimate weapon that I also got from Wreck Gar" Said Blitzwing who pulled out a Wunderwaffe Dg-2 then he aimed it at Prowl then he fired the wonder weapon hitting the ninja bot who fell "Now for you to die for good" Said Blitzwing who opened up Prowl's spark chamber, then he tore it out and crushed it with his hand. The lifeless body of Prowl turned grey. "Now for this pile of trash" Said Blitzwing who did the same to Wreck Gar, the junkion had no chance he just layed there dead "You killed my best friend you will pay" Said Derpy who flew and charged at Blitzwing only for the Decepticon to charge up his cannons and fire hitting the Pegasus burning her into ashes. "Derpy she is dead Princess what should we do" Asked Twilight "Run I will take care of him" Said Celestia with that the mane 6 ran except for Dash and Fluttershy who flew away, "I had enough you will pay for your crimes" Said Celestia who's horn began to glow "(Random) Ooooh a horn that glows let me see" Said Blitzwing who grabbed the glowing horn and yanked it off "No that is impossible how did you do that" Asked Celestia "(Hothead) easy just like this" Said Blitzwing who grabbed the princess by the wings and just pulled on them until Celestia's body was ripped in half having blood and organs spill to the floor. Blitzwing transformed into a tank and was searching for the mane 6 when he came to the castle he transformed into bot mode and blasted an entry way to the castle the guards tried there best and but perished even Shining Armor was a casualty and when Blitzwing came to the throne room which was big enough to fit him infront of the throne was the mane 6 along with Princes Luna and Cadence "Where is my Sister what happened to her" Demanded Luna "If you are talking about the princess then she well died just like you and your friends are going to do" Said Blitzwing who pulled out the Dg-2 and was about to fire when Fluttershy came up to him and gave him a sad puppy dog look and hoped that Blitzwing won't hurt her and her friends alas Blitzwing just clapped his hands together squishing the Pegasus which resulted his hands being covered in blood and some blood was on his face "(Random) Eeeewww I got blood and guts on my hands" Said Blitzwing who wiped it off on the wall which then he was about to move when suddenly an aura surrounded him and he cannot move. Infront of him were the princesses and their horns were glowing "That won't work on me" Said Blitzwing who one cannon fired a ice beam freezing the princesses and then the other cannon fired a flame melting the princesses into a puddle "(Hothead) Now you 5 will pay" Said Blitzwing who fired the Dg-2 frying the rest of the Mane 6 to death, then Blitzwing sat on the throne grinning and laughing for now he has done what Megatron and the Decepticons had failed many times to do he successfully took over a planet. Now you know what would have happened thank you for visiting the Twilight Zone.