Truth

The First Soul Born from Truth; Truth is one of The Eternal Gate Colossal Titans you'll come across in Titan Souls.

Tips for Beating
Truth is a optional multi stage boss, where you start over from phase 1 if you die.
 * 1) It start off as 2 wheels covered in eyes, with a large purple eye as a weak spot. The fight starts with the wheels spinning up power, before they position themselves horizontally and vertically. The Horizontal wheel starts off first, attempting you ram you, hitting the wall, and then recoiling. During the recoil, the Vertical wheel attempts to ram you. Once you have dodged the Vertical wheel, just shot the eye of the Horizontal. If you fail, the boss will repeat its attack
 * 2) The second phase starts off with the 2 wheels from phase 1 circling you, and they will spawn droplets attempting to float from one to the other. They will also spawn a hostile version of the droplets, with has mouths. The mouth spawns can be shot, and will also be killed by the pulled arrow. Every 4th hostile spawned will be The Purple Eye, which is this phases weak spot. It has a generous hitbox, and all you need to do is to shot it anywhere. It will try to skirt to the other eye, like a scared cat. Once it is hit, all droplets de spawn. If one of the non-hostile droplets hit you, you will be launched back and stunned for  a few seconds, which can be fatal if the hostile droplets are close.
 * 3) Final phase starts with the Eye from phase 2 growing legs. The wheels still spawns Mouth Spawns, and after spawning 2 of them, the Legged Eye will open its eyelids to fry you with a laser beam. All you have to do, is to shot its eyeball, as usual. Best of luck.

By beating The Truth you'll unlock the Truth, enabling you to be able to read the Titan (Language) and open up the hard mode.