Demon: Uriel
In Act 13, you are asked to choose a side to deliver a message to from Yamamoto the Steel-Willed, either Arcadia and the Law-oriented Messians or Souhonzan and the Chaos-oriented Gaians. The side you pick determines the Plugin that can be obtained in that specific Act.
Should you go to Arcadia, you will face the Seraph Uriel in a special boss fight, and at the end of the fight you will be asked a series of questions. The answers you need to give him to obtain his plugins are below.
For Peace
* Yes - Cooperate with the Savior
* Yes - Freedom is without order
* Yes - Pledge to fight for Millennial Kingdom
Answer correctly, and you will obtain an Inexperienced Uriel demon, as well as the Uriel Plugin: Majestic Blaze.
Dark Orb of the Inferno