The Overlord

The Overlord is an evil spirit who serves as the main antagonist of seasons 2 and 3 of LEGO Ninjago: Masters of Spinjitzu and the main antagonist of My Little Pony Transformers Prime: Twilight's Kingdom.

History
When the First Spinjitzu Master created Ninjago, the Overlord was brought to life and battled the First Spinjitzu Master for Ninjago. But before the Overlord could claim Ninjago, the First Spinjitzu Master split Ninjago in half, with the Overlord banished on the dark half.

My Little Pony Transformers Prime: Twilight's Kingdom
The Overlord later returned to Equestria, intent on stealing all Equestrian magic and having it for himself. But Lloyd Garmadon defeated him and the Overlord was sent to Tartarus, but later he escaped and tried to re-take the magic. He started with stealing Uniorn magic and was confronted by Discord and manipulated him to work with him and take his magic back. He then appears at a magic show and steals very Unicorn magic and transforms into his Golden Master form and starts stealing Pegasus and Earth Pony magic before becoming his possessed Garmadon form. He then goes to Canterlot and drains the guards and Shining Armor of their magic before going to the Princesses to drain their Alicorn magic, but once he enters the throne room, he is shocked and infuriated to discover they have no magic for him to absorb. He then imprisons them in cages and goes to absorb the magic out of Twilight's friends. He finds them and absorbs their magic and then transforms into his dragon form and then turns on Discord and drains his magic and leaves to find Twilight. He finds her

My Little Pony Transformers Prime: The Cutie Re-Mark
When Twilight, Optimus, Spike, and Starlight

Appearance in My Little Pony Transformers Prime: Twilight's Kingdom
In his first form, he is shown to be a liquid blue substance with tentacles for legs and red eyes.

In his second form after absorbing enough Unicorn magic, he is in his Golden Master armor and his tentacles are replaced with two black legs.

In his third form after absorbing Pegasus and Earth Pony magic, he is in his possessed Garmadon form.

In his fourth and final form after absorbing Twilight's friends' magic, he is in his dragon form.

Ninjago: Masters of Spinjitzu

 * The Stone Army
 * The Day Ninjago Stood Still
 * The Last Voyage
 * Island of Darkness
 * The Last Hope
 * Return of the Overlord
 * Rise of the Spinjitzu Master
 * The Surge
 * The Art of the Silent Fist
 * Blackout
 * The Curse of the Golden Master
 * Enter the Digiverse
 * Codename: Arcturus
 * The Void
 * The Titanium Ninja
 * The Corridor of Elders (flashback)

Trivia

 * It is unknown if his spirit can be destroyed. As Zane said "Defeated yes, but can he be destroyed?", it might imply that the Overlord's spirit is indestructible.