Why did Megatronus become the traitor known as The Fallen?

Why can only a PRIME beat THE FALLEN in Transformers movies. EXPLAINED

Is Megatronus Prime The Fallen In Transformers One? #transformersone #orionpax #transformers

The difference between Megatronus Prime and The Fallen. #edformers #transformers #tidal

The Fallen/Megatronus evolution (2004-2018)

THE FALLEN TRANSFORMER | Age of The Primes Megatronus The Fallen Review #transformers

megatronus/fallen when by Villain but now a hero

what if Megatronus came back as The Fallen #transformersone

Megatronus Prime/The Fallen Designs Ranked #shorts

(AGE OF THE PRIMES) Leader Class: Megatronus The Fallen #transformers

WHO IS MEGATRONUS PRIME IN TRANSFORMERS ONE

Why Did Megatronus Become The Fallen?