Who is the armored titan in "Attack On Titan"?

The Armored Titan in Attack on Titan is Reiner Braun. Reiner is a main character in the series and is initially introduced as a member of the Survey Corps fighting against the Titans alongside the protagonist, Eren Yeager. However, it is later revealed that Reiner is a traitor and has been infiltrating humanity all along as a spy for the Warriors, a group from the Marley nation. Reiner possesses the power to transform into the Armored Titan, a behemoth covered in armor that grants him incredible strength and durability. His dual identity as a warrior and a traitor creates a complex and captivating character arc throughout the series.