On Dragon-Blooded Themes
The Dragon-Blooded are Chosen of The Elemental Dragons, just as much as the Solars are Chosen of The Unconquered Sun or the Infernals are Chosen of Hell, and this manifests through inherited might. The Dragon-Blooded embody the elements of Creation and manifest this through themes of Brotherhood, Righteousness, Nobility, Soldiery, Purity and of course the Sanctity of Nature. They are individually the weakest of the Exalted and must work together for their more powerful effects, which can be seen in their more powerful Charms, and also in the Cooperative Keyword.
The Dragon-Blooded embody Brotherhood, which is quite probably one of their more important themes. The Scarlet Empress and the General Staff of Lookshy could look each other in the eyes and say "for the good of Creation" and love each other like brother and sister if they ever felt like it. All the leaders of the Great Houses could be the best of friends should the need arise. This is an easy trick for any Terrestrial to learn, and indeed is one of their signature magics.
The Dragon-Blooded demonstrate Righteousness through Charms such as Defense-From-Anathema Method or Scent-of-Crime Method. Just like Solar Larceny goes "oh you would lock your doors for the Solar Exalted, what are you some kind of HERETIC?", Dragon-Blooded Investigation goes "oy m8 are you lying to me? are you some kinda fucking criminal who would lie to the Princes of The Earth?". While Solars have Righteousness-as-Virtue, Dragon-Blooded have Righteousness-as-Law, where you gotta fucking follow the law or you're some kind of criminal.
And criminals get executed.
In Nobility we find such Charms as Sweetening The Tap Method or Jade Defense, which let you channel your SUPERIOR DECADENCE to make THE SWEETEST FUCKING WINE or be so bored that you are harder to influence. When the Draggon-Blooded channel themes of Nobility, it's because of their role in the setting as decadent nobles and the Beautiful Elite who spend the money of the Realm on their own personal interests instead of using it to better the lives of their subjects, which is a very important theme.
Through Soldiery we have most Dragon-Blooded combat Charms. This is by far their most prolific theme, and sadly also one that is extremely overused, since it relegates them to an automatic position beneath the feet of the Celestial Exalted where the only correct thing to do is for the Terrestrials to bow to their Celestial lords and masters. Sadly the writers themselves became subject to this propaganda, and currently one of the things that I am excited for is 3e's portrayal of Dragon-Blooded, which has more focus on their status as individual heroes with elemental powers who work together and embody much stronger themes of Nobility.
In Purity, we find Charms that require specific levels of Breeding to work, or Charms which increase their effectiveness with Breeding. This theme is also very prolific and just like Soldiery, doesn't have many handholds in the actual Terrestrial Charmset. Purity Charms are rare and often Essence 4+, but seem to have embedded themselves as an integral part of the Terrestrial thematics despite their rarity. Purity Charms are also a rather problematic element since they add to the general theme of "Take this much Breeding to have fun". Dreams of The First Age added Purity-Crucible Strike which can increase a character's Breeding, but it's literally a succeed-or-die Charm and is also an Elder Charm, so this is not a good fix.
Finally we have the theme of Sanctity of Nature, which is quite possibly one of their least prolific themes of all. We see a bit of it in Nature Reclaims Her Bounty and in As In The Beginning, but it is mostly relegated to Essence 5+ Charms, which tells us that it is not a core Terestrial theme unlike say; Nobility or Purity which are very important to the Terrestrial experience. Charms which possess this theme are often very obvious with their effects and possess grand and iconic effects, and of all the things that one could criticize Second Edition for, I am very happy that it added more of these Charms.
And then there is a not-quite theme, which I will call Mere Terrestrials. This theme is not as bad now as it used to be, but it used to be perhaps the most prolific theme of them all. On SpaceBattles, there were habitual questions such as "what is the appeal to playing a mook who fights in a horde?" or "why would you want to be a mere DB who is only part of a faceless horde?". It's everything bad about the Soldiery theme, but worse, it infected Second Edition and informed every consciously taken design decision that wasn't just copypasted from 1e. We can blame the terrible Portentous Comet-Deflecting Mode pseudo-Perfect on this Theme telling the writers that Terrestrials are supposed to be terrible and shitty discount Exalts.