
This Quest can be accessed at any time after unlocking the Uranus Junction on Saturn. However, completing The Duviri Paradox is not a prerequisite to start any other Main Story Quest until The Hex.
The kingdom of Duviri is a unique location in Warframe that you can access by starting The Duviri Paradox Quests. It will introduce you to the Drifter, a new playable character similar to your Operator that you will control for most of your time in Duviri, with their own set of abilities and weapons. You will be able to access a selection of random Warframes for gameplay in certain sections. This includes "loaner" Warframes and Weapons that you may not even own in your regular Arsenal, which come with preset Mod loadouts to make certain that you're always able to play.
The Duviri Paradox Quest will slowly introduce the Drifter's abilities and the world of Duviri itself. For your very first objective after the initial cutscene, however, you're quite vulnerable. It's best to simply avoid combat (using your Smoke Screen if necessary) and follow your objective markers (using the Guiding Hand ability).
The hand's guidance will eventually lead you to your Kaithe: a mounted creature you can use to traverse Duviri. This will make escaping from your pursuers much easier as you continue to follow your objectives. Eventually you will be instructed to purchase your first Drifter Intrinsic: Summon Kaithe. This will permanently allow you to call and dismiss your Kaithe instantly while inside Duviri.
To start, let's familiarize you with the Drifter's abilities!
Around the time you unlock Drifter Intrinsics, you'll also receive your trusty Sun & Moon Dual Nikanas. These two swords are your primary means of combat in The Duviri Paradox Quest. A comprehensive tutorial will show you how to fight in Duviri, but here are the basics:
After a mix of Warframe and Drifter combat to complete Quest objectives, you will gain control of a flying "dragon" known as the Orowyrm. In this cinematic sequence of the game, all you need to do is fly through Duviri, blasting your fiery breath with the fire button, and moving more-or-less the same as you would on foot or with a Railjack. However, it's worth noting that you can pitch the Orowyrm up by pressing the "jump" key and pitch it down by pressing the "crouch" key.
Now enjoy the explosive finale to The Duviri Paradox!
When The Duviri Paradox Quest is complete, you can reenter the dreamlike world at any time from your Star Chart. These methods include: The Duviri Experience, The Lone Story, and The Circuit.
The Duviri Experience is the intended way to explore Duviri. This includes side quests and activities like the board game Komi and fishing by feeding the Ravenous Maw. The Lone Story is very similar, but skips the side content to focus only on finishing a single loop of Duviri objectives. Lastly, The Circuit allows you to take preselected Warframes and Weapons to do battle in The Undercroft.
All of this content is entirely optional and not required to progress the Main Story Quests in Warframe. However, it can help you earn rewards like new Warframes (or powerful Incarnon Weapons if you play The Circuit on Steel Path difficulty). It's well worth taking a detour to explore!