Like almost every game released in the modern day, Pyre does not have classic cheat codes. But there are exploits and other ways you can cheat out advantages or even full achievements, and we'll go over a few of those now for the hardest achievements.
It all centers around the second-to-last Rite you participate in during the game's story mode. If you haven't played Pyre before, you'll know which Rite is the second-to-last because it comes immediately after the sixth Liberation Rite. The key with this Rite is that your opponent doesn't show up, and their Pyre only takes one shot to quench giving you the victory. With this, you and your fellow Exiles can do some crazy achievements without much actual effort.
Flame Quencher Achievement
If you've completed the game, you should have already gotten this achievement because it requires you to prevail in a Rite with no more than three dousings (scores). Since the second-to-last Rite only takes one dousing, congratulations.
Scribe's Champion Achievement
The Scribe's Champion achievement purports to be one of the hardest Pyre achievements to unlock, and it's not hard to see why. You have to prevail in a Campaign Rite with all 12 Titan Stars Activated on at least Standard difficulty. Most guides will suggest you use a particular assortment of Talismans, but that's unnecessary.
It seems impossible, since each Titan Star either has a negative effect on you or a positive effect on your opponents, but it's actually incredibly easy on the second-to-last Rite because you don't have an opponent. Once you get to that second-to-last Rite, just activate all the Titan Stars. Keep in mind that your Exiles earn no experience from this Rite, so you won't get the 37% bonus XP, but you will get the achievement, as well as the Scribe's Guardian and Scribe's Chosen Achievements, if you don't already have them.