Shin Megami Tensei V: Vengeance - How to fight Satan, unlock Godborn Mode, and reach level 150

Ahead of the release of Shin Megami Tensei V: Vengeance, Atlus shared that the game will newly include a "Godborn Mode" for New Game Plus, which would both raise the level of enemies to 150, as well as the max level of the Nahobino protagonist. However, there are no hints as to how to actually unlock this functionality. That's what this page is for.

Godborn Mode is unlocked by defeating the new superboss of Shin Megami Tensei V: Vengeance, Satan. But even just finding Satan can be tricky. That's because it's impossible to fight Satan on a first playthrough. You need to be at least on your first New Game Plus to even have a chance of meeting him, let alone beating him.

In order to fight Satan, here are the steps:

1.) First you need to beat Canon of Creation and achieve the "Create a World for Humanity Alone" ending, which is often considered the True or True Neutral ending to the original Shin Megami Tensei V. Once you do this, make your clear save and load a New Game Plus into Canon of Vengeance.

Update: According to an RPG Site acquaintance, you may just need any clear save for the Satan boss quest to unlock. That means you can even beat your first Canon of Vengeance playthrough, save your clear save to another save slot, and then reload your original Canon of Vengeance playthrough to see the new quest from Mastema, detailed below. 

2.) On your Canon of Vengeance playthrough, simply play your way through the game until you get to the ending sections in the Empyrean. Once you reach the Empyrean, check your Leyline Crossing maps and head Shinjuku 1st Block Leyline. You should see a quest marker near where you met Mastema, earlier in the game, and you'll be able to summon him. Complete the quest 'The Serpent King', which is always available.

3.) If you are on Canon of Vengeance, have completed the "Create a World for Humanity Alone" ending on a previous playthrough [See above update, you may just need a clear save of any kind], and completed 'The Serpent King' on the current playthrough, Mastema should have one final quest called 'The Great Adversary'. This is the new superboss quest against Satan.

4.) Defeat Satan. We'll omit a concise strategy in this guide, feel free to knock the difficulty down to Safety if you must.

Once you've defeated Satan, he'll mention the path of the Godborn. The next time you get to New Game Plus, you'll be able to select Godborn, in addition to the usual Newborn and Reborn selections.

Once Godborn is unlocked, not only can you and your demons reach level 150 with a new Moral Transcendence Miracle, but you'll also unlock Devil Lucifer for fusion (once you reach the World of Shadows in a Godborn playthrough), and you'll get the Devil Talisman.