Past chapters in the Devil May Cry series featured easter eggs and post credits footage, while Devil May Cry 5 allows players to finish the game in minutes, "simply" finishing the initial mission of the Prologue. A bit like some chapters of Ubisoft's Far Cry, Capcom has included a secret ending to unlock by performing a few actions in the final minutes.
There may be SPOILER from here on, so don't go on reading if you're not interested, for now, in how to unlock the secret finale of Devil May Cry 5.
DMC 5 | How to unlock the secret ending
In the Prologue, we play as Nero. At the beginning of the game, the protagonist will not be particularly strong, because without his demonic arm and unable to use many of his skills. This makes the boss fight with Urizen, the first one we will have to face in the game, very difficult, indeed almost impossible. The purpose of the mission is to fail, we will not, in theory, be able to face Urizen in those conditions. If we lose the battle, the story will simply go on... but here's the beauty of it.
Beating Urizen is not completely impossible and by succeeding, under those conditions of considerable disadvantage, we will be able to unlock the secret ending.
How do we beat Urizen to unlock the secret ending
Council: At first it is not worth making more attempts at this mission. Since you are free to replay every mission in the game at any time, taking all the upgrades and new skills with you, we recommend that you only try to beat Urizen in the prologue after you have already completed one or more runs. In this way, it will be a much more "fairer" fight. If you want to see this finale, we recommend you try this fight in the Demon Hunter difficulty because the subsequent unlockable ones are really much harder to deal with.
You decide whether to do it all now or wait to be stronger. Either way, here's a strategy for beating Urizen in DMC 5's Prologue.
Strategy: The key to winning this fight is to keep moving, get closer and avoid all attacks from Urizen's distance. It may seem obvious, but moving away might come naturally to you, actually, you have to get as close as possible, as the boss is extremely strong when he's keeping you at a distance and causing you a lot of damage with long range attacks. Basically, Urizen will shoot you down without getting up from the throne.
To strike Urizen directly, then, you must destroy the crystal that protects him. This crystal not only protects him from damage, but also has attacks of its own. You must get as close as possible and keep attacking the crystal until it shatters. This will leave Urizen vulnerable for a limited time, allowing you to hit it. After a while, it will summon another crystal so that you can repeat the process. If you're too far away, approach it with the Devil Bringer (which is why we've advised you to tackle the mission after one or more runs) and unload all your power, bringing along a nice set of devil breakers. And don't be stingy in using them.
Once defeated, a fun ending will be unlocked, celebrating your feat. You'll also get a trophy/goal for overcoming the tough battle. Completing this battle might also be a good way to make your bones.