Megatron/galvatron

Megatron is the decepticon leader.

Childhood
Megatron was born with his older brother Optimus Prime and was an autobot. Optimus was always there for him but Megatron trained himself harshly, making Optimus jealous.

Teens
Megatron ran into Starscream, leader of the decepticons and the two started an argument. The two were going to have a battle and Megatron said that if he wins then he will be new leader and Starscream accepted, knowing that he will win because he is older.